bluuebunny/crossref_metadata_2025 huggingface dataset:
Transgenic approach to hepatitis B Virus liver damage
Authors: Gumucio Jorge J. , McDonnell Michael W. , Van Dyke Rebecca W.
Published: March 2007

This study investigates the role of the immune system in the pathogenesis of hepatic injury during hepatitis B virus infection. A transgenic mouse line containing the gene sequences for the hepatitis B virus envelope region (pre-S1, pre-S2, and HBs Ags) ligated to mouse albumin regulatory sequences was developed. Mice of this lineage did not contract spontaneous liver disease and were immunologically tolerant to pre-S and HBs Ags. Nontransgenic mice of the same lineage were immunized with a recombinant vaccinia virus containing the coding region for the HBs polypeptide. Spleen cells from immunized mice were transferred into the transgenic mice. The recipient transgenic mice exhibited prompt falls in serum HBsAg, appearance of serum anti-HBsAg and biphasic patterns of serum ALT elevation. The first rise in serum ALT (3 to 7 days after spleen cell transfer) appeared to be due to antibody-mediated cell injury because it could be reproduced by administration of serum from immunized, nontransgenic mice to transgenic mice. The second rise in ALT, at 14 to 21 days, occurred long after disappearance of serum HBsAg and was associated with histological evidence of liver cell necrosis and infiltration of the liver by lymphocytes. In other experiments, the pattern of delayed injury was reproduced by transfer of specific cytotoxic Lyt 2+ (CD8) T cells from immunized nontransgenic mice to transgenic mice, suggesting a role for cytotoxic T lymphocyte—mediated immune injury. Further studies using a cytotoxic T lymphocyte cell line specifically sensitized to HBsAg suggested that (a) cytotoxicity was specifically directed against cells that expressed a small region of the HBsAg; (b) cytotoxicity was major histocompatibility complex—restricted (i.e. cells expressing HBsAg but not identical major histocompatibility complex antigens were not killed); (c) cytotoxicity was enhanced if target cells were pretreated with γ-interferon, which presumably enhances expression of major histocompatibility complex antigens; and (d) cytotoxicity and liver cell injury could be reproduced in vivo by transfer of HBsAg-directed cytotoxic T cell lines back into transgenic mice (which express hepatitis B antigens). In summary, transgenic mice were raised that expressed HBV-encoded antigens at the hepatocyte surface in a form recognizable by both major histocompatibility complex class I—restricted cytotoxic T lymphocytes and envelope-specific antibodies. The resultant liver cell injury indicates that chronic HBV infection may be mediated by antigenspecific, cell-mediated responses. Finally, these studies also suggest a role (perhaps minor) for viral antibodies in hepatocyte injury.
Corticosteroids and alcoholic hepatitis
Authors: Hofer Timothy , McMahon Laurence
Published: March 2007

The purpose of the study was to determine whether corticosteroids affect short-term mortality from alcoholic hepatitis. A metanalysis was conducted using studies identified through a MEDLINE computer search from 1966 to 1989 and extensive manual searches of associated bibliographies. Eleven randomized studies that assessed mortality in hospitalized patients diagnosed with alcoholic hepatitis and treated with corticosteroids were evaluated. Overall, the protective efficacy of corticosteroids was 37% (95% confidence interval 20% to 50%). Protective efficacy was higher among those trials with higher quality scores and in trials that excluded subjects with active gastrointestinal bleeding in patients with hepatic encephalopathy, protective efficacy was 34% overall (confidence interval 15% to 48%). In subjects without hepatic encephalopathy, corticosteroids were not believed to have a protective effect; this lack of efficacy was noted across all trial subgroups. Results of the metanalysis suggest that corticosteroids reduce shortterm mortality in patients with acute alcoholic hepatitis who have hepatic encephalopathy. The protective effect is dependent on exclusion of patients with acute gastrointestinal bleeding.
Functional hepatocyte heterogeneity in glutamate, aspartate and α-ketoglutarate uptake: A histoautoradiographical study†
Authors: Stoll Barbara , McNelly Sabine , Buscher Hans-Peter , Häussinger Dieter
Published: March 2007

[3H]glutamate, [3H]α-ketoglutarate or [3H]aspartate was injected in physiological concentrations into antegrade (from portal to hepatic vein) or retrograde (from hepatic to portal vein) perfused rat liver, and the tissue distribution of radioactivity was studied by histoautoradiography. Independent of the direction of perfusion, radioactivity was accumulated in a small perivenous liver parenchymal cell population, which surrounded the terminal hepatic venules as a layer of about two to five cells thick. In contrast, accumulation of radioactivity in periportal hepatocytes was low and sometimes not detectable. This distribution pattern roughly resembled that described for the immunohistochemical distribution of glutamine synthetase in liver. The present histoautoradiographic findings demonstrate a predominant uptake of vascular glutamate, aspartate and ketoglutarate into a small perivenous cell population. They confirm previous label incorporation studies in the metabolically intact liver, demonstrating an almost exclusive uptake of vascular glutamate and α-ketoglutarate into perivenous glutamine synthetase containing hepatocytes. In addition, evidence is presented suggesting that perivenous uptake of α-ketoglutarate may be one determinant for hepatic glutamine synthesis, at least under the experimental conditions used here. (Hepatology 1991;13:247-253).
Lysosomal and endosomal heterogeneity in the liver: A comparison of the intracellular pathways of endocytosis in rat liver cells
Authors: Kindberg Grete M. , Tolleshaug Helge , Gjøen Tor , Berg Trond
Published: March 2007

Air-filled albumin microspheres, asialoorosomucoid and formaldehyde-treated serum albumin are selectively taken up by endocytosis in rat liver Kupffer cells, parenchymal cells and endothelial cells, respectively. Intracellular transport and degradation of endocytosed material were studied by subcellular fractionation in sucrose and Nycodenz gradients after intravenous injection of the ligand. By using ligands labeled with 125I-tyramine—cellobiose, the subcellular distribution of labeled degradation products can be studied because they are trapped at the site of formation.

The results show that the kinetics of intracellular transport are different in hepatic parenchymal, endothelial and Kupffer cells. In endothelial cells, the ligand is associated with two types of endosomes during the first minutes after internalization and then is transferred rapidly to the lysosomes. In parenchymal cells, 125I-tyramine-cellobiose-asialoorosomucoid was located in a relatively slowly sedimenting vesicle during the first minute after internalization and subsequently in denser endosomes. Degradation of 125I-tyramine-cellobiose-asialoorosomucoid in parenchymal cells started later than that of 125I-tyramine-cellobiose-formaldehyde-treated serum albumin in endothelial cells. Furthermore, the ligand seemed to be transferred relatively slowly from endosomes to lysosomes, and most of the undegraded ligand was in the endosomes. The rate-limiting step of proteolysis in parenchymal cells is probably the transport from endosomes to lysosomes. In Kupffer cells, most 125I-tyramine-cellobiose-microspheres are found as undegraded material in very dense endosomes up to 3 hr after injection. After 20 hr, most of the ligand is degraded in lysosomes distributed at a lower density than the endosomes in Nycodenz and sucrose gradients. (Hepatology 1991;13:254-259).
Interferon-α receptor expression and regulation in chronic hepatitis B virus infection
Authors: Lau Johnson Y. N. , Sheron Nick , Morris Alan G. , Bomford Adrian B. , Alexander Graeme J. M. , Williams Roger
Published: March 2007

Interferon-α elicits antiviral and immunoregulatory activities by binding to specific receptors on the cell surface. In this study, binding characteristics of interferon-α to peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection were studied using radioiodinated recombinant interferon-α2b to determine interferon-α receptor numbers and dissociation constants. A single class of interferon-α receptor was demonstrated on peripheral blood mononuclear cells and mononuclear subsets. Peripheral blood mononuclear cells from patients with chronic hepatitis B virus infection (n = 20) and controls (n = 16) expressed a similar number of interferon-α receptors (484 ± 175 vs. 511 ± 168 sites/cell respectively, p = NS) with a similar dissociation constant (dissociation constant ± 0.2 to 0.7 nmol/L). Expression of interferon-α receptors was similar in monocyteenriched and lymphocyte-enriched fractions in both groups. Similar changes were observed in patients receiving α-interferon therapy. There was no correlation between interferon-α receptors expression and serum transaminase, serum HBsAg, serum HBV DNA, liver histological findings or the response to interferon-α therapy.

After incubation of lymphocytes in vitro with interferon-α
2b
(10 to 1,000 U/ml), interferon-α receptors number dropped by 42% to 80%, but this was associated with an increase in binding affinity (dissociation constant ≈ 0.05 to 0.15 nmol/L) in both patients and controls. There was significant delay in the initial phase of receptor recovery in the patients with chronic hepatitis B virus infection compared with normal controls (days 1 and 2, p <0.05).

These data indicate that interferon-α receptors are expressed and regulated normally in chronic hepatitis B virus infection and that the variable response to interferon-α therapy is not due to a variation in interferon-α receptor. The increase in binding affinity on interferon-α therapy may be one factor explaining why long-term interferon-α therapy is effective despite a decrease in receptor number. (Hepatology 1991;13:332-338).
Effects of ursodeoxycholic acid on serum liver enzymes and bile acid metabolism in chronic active hepatitis: A dose-response study
Authors: Crosignani Andrea , Battezzati Pier Maria , Setchell Kenneth D. R. , Camisasca Maurizia , Bertolini Emanuela , Roda Aldo , Zuin Massimo , Podda Mauro
Published: March 2007

The effect of ursodeoxycholic acid administration on liver function tests and on bile acid metabolism was investigated in 18 patients with chronic active hepatitis. Three different doses of ursodeoxycholic acid—250 mg, 500 mg and 750 mg—were administered daily to each patient for consecutive 2-mo periods. The order of doses was randomly assigned according to a replicated Latin-square design. A significant decrease in serum transaminases and γ-glutamyl transpeptidase occurred with the lowest dose of ursodeoxycholic acid, which corresponded to 4 mg/kg body wt/day, and no further significant decrease with the higher doses was seen. Biliary bile acid composition was determined by high-performance liquid chromatography and gas chromatography-mass spectrometry. At entry the relative proportions of major bile acids were similar, to those observed in normal individuals. During treatment the mean percentage of ursodeoxycholic acid in bile (22% with the 250 mg dose, 32% with the 500 mg dose and 34% with the 750 mg dose) was lower than values previously reported for patients with gallstones and normal liver function. The major bile acids were cholic, chenodeoxycholic and deoxycholic acids. A number of unusual bile acids were identified by gas chromatography-mass spectrometry, but these accounted for only 3% to 5% of the total and did not change during ursodeoxycholic acid therapy. No correlation between the improvement in liver function tests and the percentage of ursodeoxycholic acid in bile existed. These data suggest that even a slight enrichment of bile with ursodeoxycholic acid, as is attained with 250 mg/day, is effective in improving biochemical markers of liver function in patients with chronic active hepatitis. (Hepatology 1991;13:339-344).
A rat model of esophageal varices
Authors: Tanoue Kazuo , Kitano Seigo , Hashizume Makoto , Wada Hiroya , Sugimachi Keizo
Published: March 2007

We have developed a new method for inducing portal hypertension and esophageal varices in rats—partial ligation of the portal vein after devascularization of the circumference of the left renal vein and complete ligation of the portal vein on the fifth day thereafter. Thirty rats were separated into groups of 10, control (sham operation), complete portal ligation only and complete portal ligation plus devascularization. Two weeks after the surgery, the presence of esophageal varices in rats with complete portal ligation plus devas-cularization was confirmed by portography and by the histological findings. The diameter (mean ± SD) of the submucosal veins of the lower esophagus in the complete portal ligation plus devascularization group (219.4 ± 86.6 μm) was significantly larger than that in the complete portal ligation group (99.8 ± 53.4 μm) or in the control group (30.5 ± 16.6 μm) (p <0.01). Vascular structures of the lower esophagus closely resembled those in humans with esophageal varices. This new technique is simple, rapid and reliable, and application can be made to various experimental studies on portal hypertension. (Hepatology 1991;353-358).
DNA integration sites and hepatocellular carcinoma
Authors: Gumucio Jorge J. , Daugherty Daryl
Published: March 2007

This study is part of an ongoing analysis of woodchuck hepatitis virus integration sites in the host genome of hepatocellular carcinomas. The study of woodchuck hepatitis virus-DNA integration sites may shed light on the oncogenic mechanisms involved in cellular transformation and tumor formation. Viral integration enhancing cellular proto-oncogene expression is one such mechanism and has been well documented for oncogenic retroviruses such as mouse mammary tumor virus and interleukin-1. By cloning a woodchuck hepatitis virus integration site from a woodchuck hepatocellular carcinoma the authors were able to identify a new member of the myc gene family, N-myc-2. Examination of 30 additional woodchuck hepatomas revealed viral integration commonly occurred near N-myc loci with an additional five woodchuck hepatitis virus integrants near the N-myc-2 gene and one viral integrant near N-myc-1. Three of these N-myc-2 viral integrations were further evaluated and found to be localized within 200 bp of the translation stop codon. This 3′ noncoding region has recently been identified as a common site of murine leukemia virus integration in virally induced T-cell lymphomas and results in increased expression of the N-myc gene. Similar mechanisms can be proposed for hepatocellular carcinoma formation. Woodchuck hepatitis virus integration near cell-growth related protooncogenes, such as N-myc, can juxtapose viral enhancer elements and growth-regulatory genes. Virally induced overexpression of proto-oncogene messenger RNA could result from enhanced transcription or increased messenger RNA stability. To search for such effects the authors analyzed N-myc-2 RNA levels in 30 woodchuck hepatitis virus-related hepatomas. Increased levels of N-myc-2 RNA were found in 18 of 30 tumors, whereas nontumorous portions of the same livers had no detectable N-myc-2 RNA. Taken together these findings suggest that woodchuck hepatitis virus integration can result in altered N-myc-2 gene expression in a significant proportion of woodchuck hepatocellular carcinomas. The deregulation of N-myc gene expression could result in cellular transformation and ultimately tumor formation. Such examples of hepadnavirus-specific oncogenic mechanisms lend credence to theories of hepatitis B virus-induced tumorigenesis and provide models to design molecular investigations of human hepatocellular carcinoma formation.
Recombinant human α-interferon in patients with chronic non-A, non-B hepatitis: A multicenter randomized controlled trial from France
Authors: Marcellin Patrick , Boyer Nathalie , Giostra Emile , Degott Claude , Courouce Anne Marie , Degos FrançOise , Coppere Henri , Cales Paul , Couzigou Patrice , Benhamou Jean-Pierre
Published: March 2007

We have conducted a multicenter randomized controlled trial comparing two doses of recombinant human α-interferon for efficacy in 60 patients with chronic non-A, non-B hepatitis. The source of infection appeared to be transfusion in 30 patients, intravenous drug abuse in 16 patients and was unknown in 14 patients. Patients were randomly assigned to no treatment or to treatment with either 1 or 3 MU of α-interferon given three times a week for 24 wk. Forty-five patients (75%) were positive for antibody to hepatitis C virus.

During the 24-wk treatment period, mean serum ALT levels decreased in both treatment groups, but the decrease was statistically significant only in the 3 MU group. However, at 24 wk, the proportion of patients with normal ALT levels was similar in the 3 MU group (39%) and the 1 MU group (45%), and both were significantly higher than in controls (0%). Repeat liver biopsy specimens showed a significant decrease in the severity of histological changes in the 3 MU group but not in the 1 MU group or in controls. Responses to α-interferon did not correlate with patients' age, gender, source of infection, pretreatment serum ALT, presence of anti-hepatitis C virus or cirrhosis. After treatment, the mean ALT levels rose in both treated groups. The proportion of patients with normal ALT levels at wk 48 was 28% in the 3 MU group and 20% in the 1 MU group.

In conclusion, a dose of 3 MU was superior to 1 MU of α-interferon given three times weekly for 24 wk in inducing improvements in serum ALT levels and liver histological examinations. Relapse in disease activity occurred in approximately half of the responders when interferon was stopped. The response to α-interferon did not correlate with the source of infection or with the presence or absence of anti-hepatitis C virus. (Hepatology 1991;13:393-397.)
Transcatheter oily chemoembolization in the management of advanced hepatocellular carcinoma in cirrhosis: Results of a western comparative study in 60 patients
Authors: Vetter Denis , Wenger Jean-Jacques , Bergier Jean-Michel , Doffoel Michel , Bockel René
Published: March 2007

Transcatheter oily chemoembolization is widely used as palliative therapy for inoperable hepatocellalar carcinoma in high-incidence Asiatic areas. To assess its usefulness in the Western form of this cancer, 20 French patients were treated between 1987 and 1990 by intraarterial hepatic injection of a Lipiodoldoxorubicin emulsion followed by embolization with 0.5 to 1 mm gelatin sponge particles. The number of procedures ranged from one to five. All patients had advanced, symptomatic and inoperable hepatocellular carcinoma (Okuda's staging: I, n = 8; II, n = 14; III, n = 8); none was found under systematic screening. All had underlying cirrhosis (Child-Pugh's class: A, n = 15; B, n = 12; C, n = 3) that was alcoholic in origin in 27 case and posthepatitic B in origin in 3 cases. The results of the treatment were assessed by comparison with a group of 30 untreated patients admitted to the same unit between 1984 and 1987. Patients of both groups were closely matched for clinical presentation, global disease staging and precise anatomical extension. The overall 1- and 2-yr survival rate was 59% and 30%, respectively, for the treated patients vs. 0% at 1 yr for the untreated patients. The latter all died from local disease with end-stage liver failure and/or uncontrollable variceal bleeding. In the former, the three vatients with Child's class C cirrhosis died after the first procedure. During the follow-up (range = 3 to 26 mo), 11 additional patients died, 8 from metastatic generalization. In four of these cases, an adjuvant systemic chemotherapy with epirubicin was given and provided an effective response to functional symptoms in two cases (loss of pain caused by bone metastases). Fifteen autopsies were performed in the untreated group and all showed a cancerous thrombus of the main portal trunk, whereas this was found in only 1 of 10 autopsies in the treated group.

We conclude that transcatheter oily chemoembolization is an efficient palliative treatment in the Western form of hepatocellular carcinoma complieating cirrhosis; it acts as a locoregional therapy that prevents the cancerous invasion of the portal system. Further trials are needed to define the best therapy to prevent or to treat extrahepatic dissemination. (Hepatology 1991;13:427-433.)
Usefulness of pulsed doppler ultrasound in detection of angiographically evident recurrence of hepatocellular carcinoma after arterial embolization treatment
Authors: Mochida Satoshi , Hayashi Shigeki , Ogata Itsuro , Masaki Naohiko , Nagoshi Sumiko , Tomiya Tomoaki , Ohno Akihiko , Takatsuki Katsuyoshi , Ohta Yasuhiko , Yamada Shinwa , Sato Yuzuru , Ohtomo Kuni , Fujiwara Kenji
Published: March 2007

Because hepatocellular carcinoma treated by transcatheter arterial embolization often regains its size, routine follow-up is necessary. The usefulness of pulsed Doppler ultrasound for detection of this type of recurrence was compared with ultrasonography and computed tomography in 21 such hepatocellular carcinomas. Of 15 hepatocellular carcinomas diagnosed by angiography as showing recurrence, four were detected with ultrasonography and five were detected with computed tomography. Doppler signals were obtained in the peripheral portions corresponding to tumor vessels or stains on angiograms in 14 of these 15 hepatocellular carcinomas, but they were undetectable in six hepatocellular carcinomas with no recurrence. All signals disappeared after transcatheter arterial embolization. One false-negative hepatocellular carcinoma with pulsed Doppler ultrasound showed faint tumor stains on angiograms; these were also negative on ultrasonography and computed tomography. Pulsed Doppler ultrasound may be superior to ultrasonography and computed tomography as a routine procedure to detect the recurrence of hepatocellular carcinoma treated by transcatheter arterial embolization. (Hepatology 1991;13:434-437.)
Hepatic amino-nitrogen clearance to urea-nitrogen in control subjects and in patients with cirrhosis: A simplified method
Authors: Bianchi Giampaolo , Marchesini Giulio , Vilstrup Hendrik , Fabbri Andrea , De Mitri Maria Stella , Zoli Marco , Pisiél Emilo
Published: March 2007

The functional hepatic nitrogen clearance during amino acid infusion is a measure of liver cell mass. The clinical feasibility of the test has so far been limited by methodological problems. A simplified procedure was used to measure the urea-nitrogen synthesis rate and functional hepatic nitrogen clearance in nine subjects with normal liver function and in nine patients with cirrhosis. The method was based on only four consecutive 2-hr urine collections and five blood samples. Total body water was calculated from a nomogram based on age and anthropometric data, whereas the gut urea hydrolysis was assigned one fixed fraction of synthesis (0.17 in control subjects and 0.26 in patients with cirrhosis). Finally, a solution of a single amino acid, alanine, was infused as substrate for urea synthesis. Urea-nitrogen synthesis rate increased linearly with increasing α-amino-nitrogen concentration, and the slope of the regression (functional hepatic nitrogen clearance) was reduced in cirrhosis from 37.5 ± 7.0 L/hr to 18.4 ± 6.7 L/hr; p <0.005. The hepatic nitrogen clearance was linearly related to the clinical status (Child-Pugh score), to routine liver function tests and to galactose elimination capacity (r = 0.869), a wellestablished, quantitative, liver function measure.

The simplified method makes the measurement of hepatic nitrogen clearance suitable for routine clinical use. The test might prove useful to study the alterations of nitrogen metabolism in cirrhosis, with special reference to hepatic encephalopathy. (Hepatology 1991;13:460-466.)
Autoantibodies in primary biliary cirrhosis: Analysis of reactivity against eukaryotic and prokaryotic 2-oxo acid dehydrogenase complexes
Authors: Fussey Shelley P. M. , Lindsay Gordon J. , Fuller Christopher , Perham Richard N. , Dale Susan , James Oliver F. W. , Bassendine Margaret F. , Yeaman Stephen J.
Published: March 2007

Six components of the mammalian 2-oxo acid dehydrogenase complexes have previously been identified as M2 autoantigens in primary biliary cirrhosis. In this report, we present data showing that both polypeptidespecific and cross-reacting antibodies are present in patients' sera. Antibodies reacting with E2 of the pyruvate dehydrogenase complex cross-react with protein X but not with any other mammalian antigen. The main immunogenic region on protein X has been localized to within its single lipoyl domain. Polypeptide-specific antibodies bind to Elα and E1β of the pyruvate dehydrogenase complex. Antibodies reacting with the E2 polypeptides of the 2-oxoglutarate dehydrogenase complex and branched-chain 2-oxo acid dehydrogenase complex show some crossreactivity but do not recognize any of the antigens of the pyruvate dehydrogenase complex. Antibodies against the E2 component of the mammalian pyruvate dehydrogenase complex cross-react effectively with the corresponding protein from yeast but not with E2 from Escherichia coli. Antibody titer against mammalian antigens is significantly higher than against the bacterial antigens, arguing against a bacterial origin for primary biliary cirrhosis. (Hepatology 1991;13:467-474.)
Quantitation of intrinsic drug-metabolizing capacity in human liver biopsy specimens: Support for the intact-hepatocyte theory
Authors: Meyer Beat , Luo Hesheng , Bargetzi Mario , Renner Eberhard L. , Stalder Georg A.
Published: March 2007

Hepatic drug metabolism is decreased in patients with severe liver disease, but it is unclear to what extent this is due to altered hepatic blood flow or reduced intrinsic metabolic capacity. In this study we quantitated in needle-biopsy specimens the intrinsic capacity of liver tissue from 67 patients with mild liver disease (n = 36), chronic active hepatitis (n = 16) and cirrhosis (n = 15) to metabolize two model compounds in vitro. Hydroxylation of the low-extraction drug bufuralol resulted in the formation of 251 ± 25 nmol 1′OH-bufuralol/gm wet wt/hr in mildly diseased liver tissue and was significantly (p <0.01) reduced in liver tissue exhibiting chronic active hepatitis (166 ± 23 nmol/gm wet wt/hr) and cirrhosis (124 ± 21 nmol/gm wet wt/hr). The formation rates of monoethylglycinexylidide, the main metabolite of the high-extraction drug lidocaine, varied widely and were not significantly different among the three groups. To relate the drug-metabolizing capacity to the hepatocyte content of liver tissue, morphometrical study was performed in the biopsy pieces originally submitted. The metabolic activity of each biopsy piece was then related to the fractional volume of hepatocytes it was calculated to contain. In mildly diseased liver tissue 355 ± 35 nmol 1′OH-bufuralol/ml hepatocytes x hr or 12.4 ± 1.0 μmol monoethylglycinexylidide/ml hepatocytes x hr-and in cirrhotic liver tissue 306 ± 49 nmol 1′OH-bufuralol/ml hepatocytes x hr or 15.3 ± 3.0 μmol monoethylglycinexylidide/ml hepatocytes x hr-were formed, respectively, and these differences were not significant. In summary, we found that impairment of the metabolic function of cirrhotic biopsy pieces is due to a loss of hepatocytes, whereas the metabolic activity of the remaining hepatocytes is preserved. We conclude that these findings support the intact-hepatocyte hypothesis. (Hepatology 1991;13:475-481.)
The sensitized liver represents a rich source of endogenous leukotrienes
Authors: Hagmann Wolfgang , Kaiser Iris , Jakschik Barbara A.
Published: March 2007

The ability of livers to produce endogenous leukotrienes after immunological stimulation was tested with organs from rats and guinea pigs. Passive sensitization of rats in vivo with monoclonal murine antidinitrophenol-IgE before antigen challenge in the isolated perfused liver system elicited a rapid hepatic production and biliary excretion of leukotrienes as judged by radioimmunoassay after separation of individual leukotrienes by high-performance liquid chromatography. Within 10 min after antigen infusion, mainly leukotriene C4, but also leukotriene D4 and N-acetyl-leukotriene E4, appeared in the bile. The biliary excretion rate of antigen-induced cysteinyl leukotrienes rose from <2 pmol · min−1 · (kg body mass)−1 before challenge to about 30 pmol · min−1 · (kg body mass)−1 for 20 min before it declined toward prechallenge level. Quantitatively similar hepatic production of cysteinyl leukotrienes was elicited in isolated perfused guinea pig livers challenged with ovalbumin after active sensitization of the animals with ovalbumin plus Al(OH)3. To exclude extrahepatic contributions to the observed leukotriene production, both passive sensitization with anti-dinitrophenol-IgE and subsequent antigen challenge were performed on isolated rat livers perfused with blood-free medium. Such exclusively hepatic sensitization and challenge also resulted in massive production of leukotrienes. The biliary excretion rate of cysteinyl leukotrienes amounted to approximately 20 pmol · min−1 · (kg body mass)−1 during the 10 to 20 min period after antigen challenge as compared with <1 pmol · min−1 · (kg body mass)−1 before challenge. These results indicate that during anaphylaxis the liver represents a rich source of leukotrienes, and, among the cellular production sites in question, liver mast cells alone or in cooperation (e.g., with Kupffer cells) are likely candidates for such hepatic leukotriene generation. (Hepatology 1991;13:482-488.)
Ethanol increases the formation of NADP+ in rat hepatocytes
Authors: Akinshola Emmanuel B. , Potter James J. , Mezey Esteban
Published: March 2007

The acute effects of ethanol on total (bound + free) pyridine dinucleotides were determined in freshly isolated rat hepatocytes. Pyridine dinucleotides and adenine nucleotides were determined by highperformance liquid chromatography. Exposure of the hepatocytes to 8 mmol/L ethanol resulted in a decrease in NAD+ and an increase in NADP+ after 2 min incubation. There were no significant changes in NADH and NADPH. Ethanol decreased ATP and increased AMP after 2 min, whereas an increase in ADP was only apparent after 15 min of incubation. Ethanol 8 mmol/L and 100 mmol/L resulted in an increased incorporation of [32P] into NADP+ from [32P]-prelabeled NAD+ and ATP. Ethanol increased hepatocyte NAD+ kinase activity; this effect was blocked by 4-methylpyrazole but reproduced by 10 μmol acetaldehyde. These observations indicate that ethanol increases the synthesis of NADP+ and that this effect is most likely the result of increased NAD+ kinase activity. The ethanol-induced decrease of NAD+ may limit ADP ribosylation of nuclear proteins, whereas increases in NADP+ may stimulate the pentose phosphate cycle. (Hepatology 1991;13:509-14.)
Hypercholeresis induced by unconjugated bile acid infusion correlates with recovery in bile of unconjugated bile acids
Authors: Gurantz Devorah , Schteingart Claudio D. , Hagey Lee R. , Steinbach Joseph H. , Grotmol Thomas , Hofmann Alan F.
Published: March 2007

Using the isolated perfused rat and hamster liver, the relationship between bile flow, bile acid secretion rate and bile acid biotransformation after the injection of a small, bolus dose of radioactive ursodeoxycholate or of its C23 homolog, norursodeoxycholate, was examined. Ursodeoxycholate was promptly secreted into bile mostly as amino acid conjugates; <3% was secreted in unchanged form in the rat and <2% in the hamster. In contrast, norursodeoxycholate was secreted slowly, and biotransformed into glucuronide conjugates and unconjugated trihydroxy derivatives; it was also secreted in part in unchanged form. In the rat, 7% was secreted in unconjugated trihydroxy derivatives and 3% in unchanged form; in the hamster, 7% was secreted as unconjugated trihydroxy derivatives and 4% in unchanged form. The secreted bile acid species that showed the highest correlation with bile flow by far was always the unconjugated form in both rat and hamster. By multiple regression analysis, the apparent choleretic activity (microliters of induced bile flow per micromoles recovered bile acid molecules) indicated marked hypercholeresis for the unconjugated bile acid with values ranging from 100 to 300 μ/μmol. Bile flow also correlated with total bile acid recovery for ursodeoxycholate in rat and norursodeoxycholate in hamster, but in all studies the apparent choleretic activity was far lower. Other calculations indicated that most bile flow during the first 30 min was induced by secretion of the unconjugated bile acid species in all experiments, the proportion ranging from 50% to 90%. The results indicate that when a bolus of ursodeoxycholate or norursodeoxycholate is presented to the perfused rodent liver, the secretion of the unchanged bile acid appears to be responsible for most of the bile flow, probably by a cholehepatic shunting mechanism. (Hepatology 1991;13:540-550.)
Regulation of collagen production in freshly isolated cell populations from normal and cirrhotic rat liver: Effect of lactate
Authors: Cerbón-Ambriz Jorge , Cerbón-Solórzano Jorge , Rojkind Marcos
Published: March 2007

Previous work has shown that lactic acid, and to a lesser extent pyruvic acid, is able to increase collagen synthesis significantly in liver slices of CCl4-treated rats but not normal rats. The purpose of this report is to document which cells in the cirrhotic liver are responsible for the lactate-stimulated increase in collagen synthesis. It was found that (a) incorporation of 3H-proline into protein-bound 3H-hydroxyproline is increased threefold to fourfold in hepatocytes from CCl4-treated rats as compared with normal rat hepatocytes; (b) neither the hepatocytes from normal nor those from CCl4-treated rats modify their collagen synthesizing capacity when 30 mmol/L lactic acid was added to the incubation medium; (c) nonparenchymal cells obtained from livers of CCl4-treated rats synthesize much less collagen than hepatocytes, but their synthesis is stimulated twofold by lactic acid; (d) from the different nonparenchymal cells, only fat-storing (Ito) cells increase collagen synthesis when lactic acid is present in the incubation medium. These results suggest that the increased lactic acid levels observed in patients with alcoholic hepatic cirrhosis may play an important role in the development of fibrosis by stimulating collagen production by fat-storing (Ito) cells. (Hepatology 1991;13:551-556.)
Altered density of glomerular binding sites for atrial natriuretic factor in bile duct-ligated rats with ascites† ‡
Authors: Gerbes Alexander L. , Kollenda Margit C. , Vollmar Angelika M. , Reichen JÜRg , Vakil Nimish , Scarborough Robert M.
Published: March 2007

The renal response to atrial natriuretic factor is blunted in cirrhosis with ascites. This might be due to alterations of renal receptors for atrial natriuretic factor. Therefore density and affinity of glomerular atrial natriuretic factor binding sites of bile duct-ligated rats with ascites (n = 10) and of sham-operated controls (n = 10) were determined. Glomerular atrial natriuretic factor binding sites were identified to be of the B-(“biologically active”) and C-(“clearance”) receptor type. Discrimination and quantitative determination of B and C receptors for atrial natriuretic factor were achieved by displacement experiments with atrial natriuretic factor(99-126) or des(18-22)atrial natriuretic factor(4-23), an analogue binding to C receptors only. Density of total glomerular atrial natriuretic factor binding sites was significantly increased in bile duct-ligated rats (3,518 ± 864 vs. 1,648 ± 358 fmol/mg protein; p < 0.05). This was due to a significant increase of C-receptor density (3,460 ± 866 vs. 1,486 ± 363 fmol/mg protein; p < 0.05), whereas density of B receptors was not significantly different in bile duct-ligated rats (58 ± 11 vs. 162 ± 63 fmol/mg protein). Affinity of atrial natriuretic factor to its glomerular binding sites did not differ significantly between both groups. These data suggest that an altered glomerular atrial natriuretic factor receptor density could be involved in the renal resistance to atrial natriuretic factor in cirrhosis with ascites. (Hepatology 1991;13:562-566.)
A new method to monitor Kupffer cell phagocytosis continuously in perfused rat liver
Authors: Ganey Patricia E. , Keller Barbara , Lichtman Steven N. , Lemasters John J. , Thurman Ronald G.
Published: March 2007

A new method was developed to monitor Kupffer cell phagocytosis continuously in perfused liver using a fluorescent probe, rhodamine-gelatin, synthesized from gelatin and rhodamine isothiocyanate. In perfused rat liver, phagocytosis by Kupffer cells was assessed both by uptake of the dye and from fluorescence measured from the liver surface. Uptake of rhodamine-gelatin and surface fluorescence (520 → 585 nm) increased as perfusate concentrations of rhodamine-gelatin were elevated. Histological examination revealed that fluorescence caused by rhodamine-gelatin was concentrated in cells lining the sinusoid. Furthermore, when hepatic parenchymal, endothelial and Kupffer cells were isolated by centrifugal elutriation after pretreatment in vivo with rhodamine-gelatin, the fluorescent label was detected nearly exclusively in the Kupffer cell fraction. Fluorescence of rhodamine-gelatin from the liver surface was directly proportional to uptake of rhodamine-gelatin, indicating that measurement of surface fluorescence could be used as an index of phagocytic activity of Kupffer cells. Uptake of rhodamine-gelatin and fluorescent labeling of sinusoidal cells were inhibited nearly completely by dextran sulfate, which decreases phagocytic activity, and were increased by about 50% by pretreatment with endotoxin, which stimulates phagocytosis. This new method was combined with standard procedures to monitor parenchymal cell function (e.g., oxygen uptake and release of lactate dehydrogenase), Kupffer cell phagocytic activity and parenchymal cell injury simultaneously during perfusion with the hepatotoxicant allyl alcohol. Activation of phagocytosis by Kupffer cells monitored by rhodamine-gelatin fluorescence occurred within 5 min of addition of allyl alcohol. On the other hand, parenchymal cell injury, assessed from release of lactate dehydrogenase, did not begin until 40 min and reached maximal values at around 90 min. Thus stimulation of Kupffer cell phagocytic activity preceded parenchymal cell injury during exposure to allyl alcohol. Moreover, parenchymal cell injury caused by allyl alcohol was enhanced by pretreatment with endotoxin, suggesting that release of toxic mediators from Kupffer cells participates in the mechanism of toxicity caused by allyl alcohol. This new method makes it possible to monitor function and viability of Kupffer and parenchymal cells simultaneously during exposure to toxic agents in perfused liver. (Hepatology 1991;13:567-574.)
Trolox protects rat hepatocytes against oxyradical damage and the ischemic rat liver from reperfusion injury
Authors: Wu Tai-Wing , Hashimoto Noriaki , Au Jian-Xun , Wu Jun , Mickle Donald A. G. , Carey Doug
Published: March 2007

Trolox, a hydrophilic analog of vitamin E, was reported to scavenge peroxyl radicals from artificial systems better than its parent compound. Here we examined the possible cytoprotective effect of Trolox in cultured hepatocytes and in the rat liver.

In cultured rat hepatocytes, 0.5 to 16 mmol/L Trolox (with optimum between 1 to 2 mmol/L) was observed to prolong the survival of cells exposed to oxyradicals generated with xanthine oxidase-hypoxanthine. The protection by 1 mmol/L Trolox surpassed that provided by either ascorbate, mannitol, superoxide dismutase and/or catalase-each at a level giving its maximal protection in the same system. In both a global and partial model of hepatic ischemia-reperfusion in rats, infusion of Trolox (7.5 to 10 μmol/kg body weight) just before reflow reduced by > 80% the liver necrosis sustained in untreated (no Trolox) control rats. Such organ salvage was apparently accompanied by ˜ 50% reduction in the amount of hepatic conjugated dienes, which were quantified by a highly specific radiochemical assay. Since conjugated dienes are presumed to be good “markers” of oxyradical damage, our data may have provided a semiquantitative link between free radical-induced necrosis and its chemical imprint in vivo. The data also indicated a relatively rapid and potent antioxidant-like action by Trolox on rat hepatocytes and on the postischemic reperfused rat liver. (Hepatology 1991;13:575-580.)
Brown pigment gallstones: The role of bacterial hydrolases and another missed opportunity
Authors: Gumucio Jorge J. , Ostrow Donald J.
Published: March 2007

The bile acids in brown pigment stones and gallbladder bile were fractionated into free acids, glycine and taurine conjugates, and sulfates, using diethylamino-hydroxypropyl-Sephadex LH-20 (DEAPLH-20) column chromatography, and were quantitated by gas chromatography. Twenty-eight cases of brown pigment stones were studied and divided into two groups: those with and those without bacteria possessing bile acid-deconjugating activity. In the former, free bile acid amounted to 62 ± 34% of the total bile acid, while in the latter, only 0.1% of total bile acid was free bile acid. The fraction of total bile acid made up of free bile acids was found to be consistently higher in brown pigment stones than in the corresponding bile, irrespective of the presence or absence of biliary infection. Free bile acid is present in negligible amounts in normal bile. Total bile acid concentration in the bile of patients with brown pigment stones was significantly less than that of controls (13 vs. 50 mg/ml). Biliary infection is almost always present in cases with brown pigment stones. These findings suggest that bacterial infection is present at the initiation of brown pigment stone formation as well as during the period of ensuing stone growth.
Incidence, determinants and significance of delayed clearance of serum HBsAg in chronic hepatitis B virus infection: A prospective study
Authors: Liaw Yun-Fan , Sheen I-Shyan , Chen Tong-Jong , Chu Chia-Ming , Pao Chia-C
Published: March 2007

To investigate the incidence, determinants and significance of delayed clearance of serum HBsAg in chronic hepatitis B virus infection, a prospective follow-up study was conducted in two consecutive groups of patients. Group I consisted of 984 patients (859 men and 125 women) with biopsy-proven chronic type B hepatitis, whereas group II consisted of 1,598 asymptomatic chronic carriers (998 men and 600 women) with normal serum aminotransferase activity. During a mean follow-up period of 4.0 ± 2.3 yr, 19 patients (1.9%) of group I cleared HBsAg from their serum, whereas 35 patients (2.2%) in group II did so in a mean follow-up period of 2.7 ± 1.4 yr. The annual incidence of delayed serum HBsAg clearance was 0.5% in group I and 0.8% in group II (p < 0.02). The cumulative probability of HBsAg clearance was also higher in group II than in group I (p <0.007). Antibodies to HBsAg developed in 9 patients (47.4%) with chronic hepatitis and in 11 (31.4%) asymptomatic carriers who cleared serum HBsAg. Those who were HBeAg negative and those older than 40 at entry and those who exhibited cirrhosis during follow-up had a higher incidence of delayed HBsAg clearance. Gender, initial histological changes and hepatitis delta virus infection did not influence the occurrence of HBsAg clearance. Serum HBV DNA was not detectable by slot-blot hybridization but was still detectable by polymerase chain reaction in serum specimens collected within 1 yr of HBsAg clearance. Liver biopsy performed later in 10 patients showed no significant hepatitis activity or tissue HBV DNA, HBsAg or HBcAg. The results suggest that the incidence of delayed clearance of HBsAg during chronic HBV infection is low. HBeAg status, age of patients and development of cirrhosis are determinants for HBsAg clearance. (Hepatology 1991;13:627-631.)
Immune response of peripheral blood mononuclear cells to HBx-antigen of hepatitis B virus
Authors: Jung Maria-Christina , Stemler Marietta , Weimer Thomas , Spengler Ulrich , Döhrmann Jutta , Hoffmann Robert , Eichenlaub Dieter , Eisenburg Josef , Paumgartner Gustav , Riethmüller Gert , Will Hans , Pape Gerd R.
Published: March 2007

The hepatitis B virus genome encodes a transcriptional transactivator protein designated HBxAg. We have investigated whether this antigen is a target structure for human T-lymphocytes. Using recombinant HBxAg protein, we found HBxAg-specific stimulation of peripheral blood mononuclear cells in patients with acute hepatitis B virus infection (6 of 6) and chronic hepatitis B virus infection (6 of 17) but not in healthy individuals. With HBxAg-specific synthetic polypeptides, several T-cell epitopes were identified. Most were located in the carboxyterminal half of the HBxAg protein. Five T-cell clones specific for a T-cell epitope located at the carboxyterminal region of HBxAg were established and found to belong to the CD2/CD4-positive, CD8-negative subtype. These data establish for the first time HBxAg as an antigen in the cellular immune response. (Hepatology 1991;13:63-643.)
Expression of insulin-like growth factor II, α-fetoprotein and hepatitis B virus transcripts in human primary liver cancer
Authors: Cariani Elisabetta , Lasserre Chantal , Kemeny François , Franco Dominique , Brechot Christian
Published: March 2007

Insulin-like growth factor II is a fetal growth factor structurally and functionally related to insulin and insulin-like growth factor I. Its mRNA expression is developmentally regulated in human liver, the reexpression of insulin-like growth factor II fetal transcripts being often observed in primary liver cancer. Insulin-like growth factor II and α-fetoprotein mRNAs were studied in 16 human primary liver cancers, most of which were highly differentiated. Hepatitis B virus transcripts were also analyzed in the tumors from hepatitis B virus chronic carriers. α-Fetoprotein mRNA was detected in only four tumors and in one nontumorous cirrhotic tissue; all these samples also displayed insulin-like growth factor II fetal transcripts. Furthermore, fetal insulin-like growth factor II mRNAs were observed in five tumors and six nontumorous cirrhotic areas not expressing α-fetoprotein mRNA. The presence of hepatitis B virus RNA was only observed in tissues not expressing α-fetoprotein or fetal insulin-like growth factor II mRNA. In conclusion, fetal insulin-like growth factor II transcripts are more frequently observed than α-fetoprotein mRNA in highly differentiated liver cancers and in surrounding cirrhotic areas. The reexpression of fetal insulin-like growth factor II transcripts might then be a marker of early steps of liver cell transformation. (Hepatology 1991;13:644-649.)
Incidence of parenchymal liver diseases in Denmark, 1981 to 1985: Analysis of hospitalization registry data
Authors: Almdal Thomas P. , Sørensen Thorkild I. A.
Published: March 2007

The sex-specific and age-specific incidence rates of the major parenchymal liver diseases in a North European population were estimated using a computerized registry of all admissions to somatic hospitals in Denmark.

The incidence was calculated by counting all incident cases of these diseases reported to the registry in the 5-yr period 1981 to 1985 and dividing the number of cases by the number of person-years at risk in this period.

The incidence rates (per million person-years) were for men and women, respectively: infectious hepatitis, 109 and 71; toxic hepatitis, 19 and 22; chronic hepatitis, 27 and 29; alcoholic cirrhosis, 190 and 85; nonalcoholic nonbiliary cirrhosis, 110 and 82; primary biliary cirrhosis, 4 and 14. The pattern of the age-specific incidence rates was similar in men and women in infectious hepatitis, alcoholic cirrhosis, nonalcoholic nonbiliary cirrhosis and primary biliary cirrhosis. Toxic and chronic hepatitis had a higher incidence in women than in men only in older age groups. The incidence of idiopathic hemochromatosis, Wilson's disease, secondary biliary cirrhosis, portal vein thrombosis and Budd-Chiari's syndrome were less than four in both sexes. (Hepatology 1991;13:650-655.)