bluuebunny/crossref_metadata_2025 huggingface dataset:
Comitogenic effects of estrogens on DNA synthesis induced by various growth factors in cultured female rat hepatocytes
Authors: Ni Nan , Yager James D.
Published: March 2007

Ethinyl estradiol is a weak complete carcinogen and potent tumor promoter. In vivo, ethinyl estradiol causes a rapid but transient increase in liver growth, whereas in cultured female hepatocytes it enhances DNA synthesis induced by epidermal growth factor and is thus classified as a comitogen. The objectives of this study were to determine: (a) whether estradiol also has comitogenic activity; (b) whether the comitogenic effects of estrogen extend to complete hepatic mitogens other than epidermal growth factor and (c) whether inhibition of hepatocyte DNA synthesis by transforming growth factor-β can be blocked by estradiol. Female rat hepatocytes in primary culture were exposed to estradiol with and without various growth factors, and we determined DNA synthesis by measuring [3H]thymidine incorporation into extracted DNA or by determining the nuclear labeling index by means of autoradiography. The results show that estradiol, like ethinyl estradiol, has comitogenic activity for epidermal growth factor, although it is somewhat less potent. Four complete hepatic mitogens showed different abilities to stimulate DNA synthesis, with hepatocyte growth factor > transforming growth factor-alpha > epidermal growth factor > acidic fibroblast growth factor. Estradiol enhanced DNA synthesis occurring in response to all four of these complete hepatic mitogens. This finding suggests that the mechanism of estrogen comitogenesis may involve effects at a point where the different signal-transduction pathways leading from the growth factors converge. The level of estrogen-mediated enhancement of DNA synthesis was similar for all four mitogens, ranging from 1.5- to 2.2-fold, depending on the experiment. Furthermore, determination of the nuclear labeling index showed that estrogen enhancement of DNA synthesis was associated with an increase in the percentage of hepatocytes that responded to the growth factors. Finally, estradiol did not specifically block the growth-inhibitory effects of transforming growth factor-β. (Hepatology 1994;19:183-192).
Hemodynamic changes after ligation of a major branch of the portal vein in rats: Comparison with rats with portal vein constriction
Authors: Um Soonho , Nishida Osamu , Tokubayashi Masaki , Kimura Fumiko , Takimoto Yukinobu , Yoshioka Hideyuki , Inque Ryoichi , Kita Toru
Published: March 2007

In chronic portal-hypertensive rat models, such as portal vein constriction or cirrhosis, the portal blood flow that effectively perfuses the hepatocytes is substantially reduced because of anatomical or functional shunts. It is possible therefore that a feedback mechanism from the liver to the splanchnic bed is responsible for the splanchnic hyperemia observed in chronic portal hypertension. To investigate the possible role of such a feedback mechanism, we examined the chronological changes in both portal and systemic hemodynamics in rats after ligation of a major branch of the portal vein that supplies about 80 of the liver circulation. Rats submitted to sham surgery and portal vein-constricted rats were also studied. Blood flow and portal-systemic shunting were measured by radioactive microsphere techniques. For 7 days after portalbranch ligation, transient portal hypertension resulted from an elevated portal resistance. However, no significant changes in portal venous inflow or splanchnic arteriolar resistance were found in the portal branch-ligated rats, whereas in the portal vein-constricted rats significant hyperdynamic changes in these parameters were noted. On the other hand, transient hyperdynamic changes occurred in the systemic circulation during the period from the fourth to the sixth day after portal-branch ligation, similar to those observed in the portal vein-constricted rats. The lack of hyperdynamic changes in the portal territory of the portal branch-ligated rats suggests that the splanchnic hyperemia found in chronic portal-hypertensive states is unlikely to be caused by a feedback mechanism from the ischemic hepatic parenchyma. The transient development of a systemic hyperdynamic circulation during the period when the perfused liver mass has not yet fully hypertrophied after portalbranch ligation suggests that such a hyperdynamic change may be related to the impairment of hepatic function. (Hepatology 1994;19:202-209).
Buoyant density of hepatitis C virus recovered from infected hosts: Two different features in sucrose equilibrium density-gradient centrifugation related to degree of liver inflammation
Authors: Kanto Tatsuya , Hayashi Norio , Takehara Tetsuo , Hagiwara Hideki , Mita Eiji , Naito Masafumi , Kasahara Akinori , Fusamoto Hideyuki , Kamada Takenobu
Published: March 2007

Hepatitis C virus is reported to have a low buoyant density in sucrose. To determine the density of hepatitis C virus in the circulation of infected hosts and its association with the degree of liver inflammation, we examined serum samples from 10 patients who were positive for both hepatitis C virus antibody (C100 antigen) antibody and serum hepatitis C virus RNA. After the serum was ultracentrifuged in sucrose density gradient (10 to 60), the hepatitis C virus RNA titer in each collected fraction was quantified by means of competitive reverse transcription-polymerase chain reaction. In samples from five blood donors, the hepatitis C virus RNA titer had a single peak at fractions with densities of 1.08 to 1.11 gm/ml. In samples from five patients with ALT abnormalities, the titer had two peaks at fractions with 1.09 to 1.10 gm/ml and 1.22 to 1.25 gm/ml. After the selected samples were treated with detergents and ultracentrifuged, the titer in the 1.08 to 1.11 gm/ml fractions decreased and that in the 1.22 to 1.25 gm fractions increased. This result implied that the hepatitis C virus density changed with removal of the viral envelope by lipid solvents. Thus the buoyant density of hepatitis C virus in sucrose was 1.08 to 1.11 gm/ml for an intact virion and 1.22 to 1.25 gm/ml for what was presumed to be a nucleocapsid. These results demonstrated that HCV virion is a dominant form in the circulation of blood donors without ALT abnormalities. In patients with liver inflammation HCV particles with higher densities of 1.22 to 1.25 gm/ml coexist with virion in the circulation, which might be presumed nucleocapsids. (Hepatology 1994;19:296-302).
Quantitative assessment of serum IgM anti-HBc in the natural course and during interferon treatment of chronic hepatitis B virus infection
Authors: Marinos George , Smith Heather M. , Naoumov Nikolai V. , Williams Roger
Published: March 2007

Serum IgM anti-HBc was determined in 135 chronic HBsAg carriers with various categories of histological activity on liver biopsy and hepatitis B serological profile. Thirty-three patients were treated with interferon-α to investigate the correlation between serum IgM anti-HBc with histological activity and viral replication, to evaluate the usefulness of pretreatment IgM anti-HBc as a predictor of a successful response to interferon-α and to examine the IgM anti-HBc response during this treatment. All 53 patients with chronic active hepatitis with either wild-type (n = 42) or precore mutant variant HBV infection (n = 11) had an IgM anti-HBc index greater than 0.300 compared with 7.4 (2 of 27) of the chronic HBsAg/HBeAg-positive carriers with chronic persistent hepatitis, 10 (3 of 30) of the anti-HBe-positive asymptomatic carriers and none of the 25 patients with hepatitis D virus-positive chronic active hepatitis (p < 0.0001). Pretreatment IgM anti-HBc index was greater than 0.300 in 82.4 (14 of 17) of HBeAg/HBV DNA-positive patients who seroconverted after interferon-α treatment compared with 25 (4 of 16) of the patients who did not seroconvert (p = 0.0013), whereas an elevated pretreatment AST was present in only 52.9 (9 of 17) of responders and in 37.5 (6 of 16) of nonresponders (p = 0.42). Serial testing of IgM anti-HBc in these 33 patients during interferon-α treatment showed a significant rise in IgM anti-HBc in all responders, which followed the AST flare-up but preceded the time of the HBeAg to anti-HBe seroconversion. The data presented indicate that serum IgM anti-HBc is a good surrogate marker for hepatocellular damage immunopathologically related to hepatitis B virus and is a better predictor of a beneficial response to interferon-α treatment than serum AST. IgM anti-HBc indicates the induction of the immune response to HBcAg during the course of chronic HBV infection but is not directly involved in the elimination of the infected hepatocytes. (Hepatology 1994;19:303-311).
Acute fatty liver of pregnancy and long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency†
Authors: Treem William R. , Rinaldo Piero , Hale Daniel E. , Stanley Charles A. , Millington David S. , Hyams Jeffrey S. , Jackson Sandra , Turnbull Douglass M.
Published: March 2007

The pathogenesis of acute fatty liver of pregnancy is unknown, but similarities in the clinical presentation and the histological appearance of the liver with those found in children with metabolic defects in the intra-mitochondrial β-oxidation pathway of the liver suggest that a disturbance in hepatic fatty acid oxidation may play a role. We report a woman with acute fatty liver of pregnancy who gave birth to a seemingly normal full-term infant who was seen at 4 mo of age with hypoglycemia, coma and profound hepatic steatosis. The infant had a defect in fatty acid oxidation, long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency, and the mother proved to be heterozygous for this metabolic condition. We hypothesize that the interaction of an affected fetus with a female heterozygous for this defect in fatty acid oxidation in the late third trimester accounts for some cases of acute fatty liver of pregnancy. (Hepatology 1994;19:339-345).
Diuretics vs. paracentesis followed by diuretics in cirrhosis: Effect on ascites opsonic activity and immunoglobulin and complement concentrations
Authors: Ljubičić Neven , Bilić Ante , Kopjar Branko
Published: March 2007

Ascitic fluid opsonic activity and ascitic fluid C3 concentrations are important protective factors against spontaneous bacterial peritonitis. This randomized controlled study was performed to compare the effect of diuretic administration alone vs. single large-volume therapeutic paracentesis followed by administration of diuretics on ascitic fluid opsonic activity and on ascites and serum immunoglobulin and complement concentrations in patients with alcoholic cirrhosis and tense ascites. Twenty-one patients were randomly allocated to two groups: group 1 included 11 patients who were treated with diuretics alone, and group 2 included 10 patients who were treated with single large-volume therapeutic paracentesis (5 to 6 L of ascites removed) followed by diuretics. Ascitic fluid opsonic activity and serum and ascites immunoglobulin and complement concentrations were measured at the beginning and at the end of treatment. The ascitic fluid opsonic activity increased significantly in patients treated with diuretics alone (p < 0.05), whereas in the group of patients treated with therapeutic paracentesis followed by diuretics, the ascites opsonic activity remained stable. Although ascitic fluid IgG, IgA and C3 concentrations increased significantly in patients treated with diuretics alone (p < 0.05), ascitic fluid C3 concentration significantly decreased in patients from group 2 (p < 0.05), whereas IgG and IgA concentrations remained unchanged. However, in both groups of patients serum immunoglobulin and complement concentrations remained unchanged. This study suggests that in cirrhotic patients with tense ascites, treatment with diuretics alone may have the potential advantage over single large-volume therapeutic paracentesis followed by the administration of diuretics of providing better protection from spontaneous bacterial peritonitis. However, further investigations are necessary to demonstrate the relevant clinical incidence of spontaneous bacterial peritonitis in cirrhotic patients with tense ascites treated either with diuretics alone or with single large-volume therapeutic paracentesis followed by diuretics. (Hepatology 1994;19:346-353).
Reperfusion injury, antioxidants and hemodynamics during orthotopic liver transplantation
Authors: Goode Helen F. , Webster Nigel R. , Howdle Peter D. , Leek Jack P. , Lodge J. P. A. , Sadek Sammi A. , Walker Barry E.
Published: March 2007

Endothelial injury occurs as a result of oxygen free radical production after ischemia and reperfusion of transplanted livers, causing hemodynamic disturbance. Patients with chronic liver disease generally have low levels of fat-soluble vitamins, which have important antioxidant roles. We therefore assessed circulating levels of the antioxidants vitamin A, vitamin E, β-carotene and lycopene, indices of lipid peroxidation and hemodynamic changes during elective orthotopic liver transplantation in 12 patients. We found that initial antioxidant levels were severely depleted compared with healthy subjects, and in some patients carotene and lycopene levels were undetectable. Increased lipid peroxidation was also evident, as shown by thiobarbituric acid-reactive substances. On reperfusion of the liver graft, vitamin A and E levels fell (p < 0.01) and were associated with decreases in systemic vascular resistance (p < 0.02). These data show that patients undergoing liver transplant have lowered antioxidant defenses and evidence of free radical damage, which compound the additional insult of reperfusion injury. Antioxidant therapy in these patients before transplantation may ameliorate the effects of reperfusion. (Hepatology 1994;19:354-359).
Acetaldehyde-modified epitopes in liver biopsy specimens of alcoholic and nonalcoholic patients: Localization and association with progression of liver fibrosis†
Authors: Holstege Axel , Bedossa Pierre , Poynard Thierry , Kollinger Michael , Chaput Jean Claude , Houglum Karl , Chojkier Mario
Published: March 2007

Acetaldehyde, the first product of ethanol oxidation, has been shown to stimulate collagen gene expression and to form protein-acetaldehyde adducts. Because little is known about these adducts in human liver tissue, we assessed, with an immunohistochemical procedure, the presence and location of acetaldehyde-protein adducts in liver biopsy specimens of alcoholic patients. In addition, we correlated the presence of adducts with the progression or subsequent occurrence of liver fibrosis. The group included 106 patients with high alcohol consumption (>90 gm ethanol/day for the last 5 yr), 10 nonalcoholic patients with normal livers and 23 patients with other liver diseases. Sixty-four of the 106 alcoholic patients had a second liver biopsy, whose specimen was used to assess the progression of liver fibrosis. Polyclonal antibodies were produced against homologous low-density lipo-protein purified from rabbit serum and modified in vitro in the presence of acetaldehyde. Protein-acetaldehyde adducts could be detected by immunohistochemistry in biopsy specimens of 90 alcoholic patients (85), in none of the 10 nonalcoholic patients with normal livers and in 65 of the patients with nonalcoholic liver disease. Acetaldehyde-modified epitopes were detected in the intracellular and extracellular compartment. Intracellular protein-acetaldehyde adducts were localized in the cytoplasm of hepatocytes with a more intense staining in zone 3. No correlation existed between the intensity of intracellular staining and the histologically assessed severity of liver disease. Extracellular acetaldehyde-modified epitopes were detected in 55 (52) biopsy specimens of alcoholic patients, with 33 of 39 (85) patients with alcoholic hepatitis or alcoholic hepatitis in cirrhosis, in none of the 10 nonalcoholic patients with normal livers and in 3 (13) of 23 patients with other liver diseases. Extracellular protein-acetaldehyde adducts were colocalized within the extracellular matrix. A brighter staining was seen in areas of histologically assessed active fibrogenesis and no or low staining in the well-organized older fibrous tissue. The presence of extracellular acetaldehyde adducts in the first biopsy specimen was significantly correlated to progression of liver fibrosis in the second biopsy specimen (p < 0.05). The results of our study indicate that covalent crosslinks between acetaldehyde and proteins could be involved in the pathogenesis of liver fibrosis. (Hepatology 1994;19:367-374).
Protective effect of the lazaroid U74006F in cold ischemia-reperfusion injury of the liver
Authors: Cosenza Carlos A. , Cramer Donald V. , Cunneen Scott A. , Tuso Phillip J. , Wang Hong K. , Makowka Leonard
Published: March 2007

Lipid peroxidation may play a major role in the loss of liver graft viability after prolonged cold ischemia and reperfusion injury. The lazaroid compound U74006F is a potent inhibitor of lipid peroxidation, and this study was designed to evaluate the efficacy of this compound in preventing cold ischemia-reperfusion damage in three different models: pig endothelial cells in culture, ex vivo isolated pig liver perfusion and orthotopic transplantation of syngeneic rat livers. The addition of U74006F to University of Wisconsin preservation solution significantly prolonged endothelial cell viability after 48 and 72 hr of cold ischemia and reoxygenation (p < 0.01). Donor pigs were injected with vehicle or U74006F (4.5 mg/kg) before liver harvest. After 24 hr of cold storage in University of Wisconsin solution, the livers were perfused with pig blood for 180 min in an isolation chamber. Measurements of liver function parameters, including AST, ALT, bile production, superoxide anion and phospholipase A2 release, were assessed every 60 min. Although bile production was similar in the U74006F-treated and control groups, significant decreases of AST and ALT levels (p < 0.01) in the perfusate of the livers from treated donors were observed. In addition, the U74006F group displayed significantly reduced release of superoxide anion and phospholipase A2 compared with these parameters in the untreated group (p < 0.05 and p < 0.01, respectively). In the last model, donor rats were treated with U74006F before harvest; the rat liver grafts were preserved in cold University of Wisconsin solution for 24 hr and then transplanted into recipient rats. The number of liver graft recipients that survived 7 days after transplantation was significantly larger (p < 0.001) in the group of recipients of U74006F-treated livers. Furthermore, this group showed significantly lower levels of lipid peroxides in liver tissues (p < 0.01) and AST and ALT release (p < 0.05) compared with the control group at 2 and 7 days after transplantation. We conclude that U74006F is effective in enhancing the resistance of the liver to damage due to cold ischemia-reperfusion injury and that the use of this compound may improve early liver graft function after transplantation. (Hepatology 1994;19:418-425).
Regenerative changes in C/EBPα and C/EBPβ expression modulate binding to the C/EBP site in the c- fos promoter
Authors: Diehl Anna Mae , Yang Shi Qi
Published: March 2007

CCAAT/enhancer binding proteins are a family of basic zipper DNA binding proteins that regulate transcription of several liver-specific genes and certain growth-related genes. Growth-related variations in the nuclear expression of one or more of the CCAAT/enhancer binding proteins may regulate the transition from the nonproliferative, differentiated phenotype of adult liver to the proliferative phenotype of regenerating liver. To evaluate this possibility, we used Northern- and Western-blot analyses to profile the expression of selected CCAAT/enhancer binding proteins in regenerating liver. Variations in CCAAT/enhancer binding protein expression were then correlated with changes in binding to the CCAAT/enhancer binding protein site of the c-fos promoter. Expression of both CCAAT/enhancer binding protein α and CCAAT/enhancer binding protein β increases after partial hepatectomy. Steady-state levels of CCAAT/enhancer binding protein α mRNA increase 30 within an hour of partial hepatectomy (p < 0.05). This is followed by a transient increase in nuclear levels of CCAAT/enhancer binding protein α protein at 3 hr after partial hepatectomy (p = 0.08). In contrast, increases in CCAAT/enhancer binding protein β mRNA and protein are more sustained. Levels of CCAAT/enhancer binding protein β mRNA increase 400 to 500 within an hour of partial hepatectomy and remain increased throughout most of the prereplicative period (p < 0.01). Nuclear levels of CCAAT/enhancer binding protein β protein are 200 to 300 greater than prehepatectomy levels at 3 hr (p < 0.001) to 6 hr (p < 0.05) and do not approach basal levels until 24 hr after partial hepatectomy. Gel mobility shift assays of nuclear extracts from regenerating livers indicate that these increases in nuclear protein expression are associated with increased DNA binding of CCAAT/enhancer binding protein α-β heterodimers and β-β homodimers. These results demonstrate growth-related variations in the expression and DNA binding of both CCAAT/enhancer binding protein α and β during liver regeneration and support the theory that altered CCAAT/enhancer binding protein DNA binding may contribute to regeneration-associated changes in liver cell phenotype. (Hepatology 1994;19:447-456).
Modulation of hepatic sinusoidal endothelial cell function by Kupffer cells: An example of intercellular communication in the liver
Authors: Deaciuc Ion V. , Bagby Gregory J. , Niesman Michael R. , Skrepnik Nebojsa , Spitzer John J.
Published: March 2007

We tested the hypothesis that Kupffer cells modulate sinusoidal endothelial cell function in the liver. Rats were treated with Kupffer cell-depleting agents (gadolinium chloride and liposome-encapsulated dichloromethylene diphosphonate) or with inhibitors of phospholipase A2 or leukotriene A4 synthase (dexamethasone and diethylcarbamazine, respectively). Hyaluronan uptake by the isolated, perfused liver was measured as an index of the functional state of the sinusoidal endothelial cell. Plasma hyaluronan concentration was also determined. Three hours after Escherichia coli lipopolysaccharide administration (100 μg/100 gm body wt, intravenously) plasma hyaluronan levels were significantly increased (280 to 320), whereas hepatic hyaluronan uptake was markedly decreased (approximately 76). Pretreatment with gadolinium chloride (0.5 mg/100 gm body wt, intravenously, 21 hr before saline solution or lipopolysaccharide administration), liposome-encapsulated dichloromethylene diphosphonate (40 μmol/100 gm body wt, intravenously, 44 hr before saline solution or lipopolysaccharide injection), dexamethasone (40 μg/100 gm body wt, intravenously, 1 hr before saline solution or lipopolysaccharide administration) or diethylcarbamazine (repeated doses, 10 mg/100 gm body wt, intravenously, 1 hr before saline solution or lipopolysaccharide injection) counteracted the lipopolysaccharide inhibitory effect on hepatic hyaluronan uptake. With the exception of gadolinium chloride, all other agents also prevented the lipopolysaccharide-induced increase in plasma hyaluronan concentration. Gadolinium chloride only attenuated the lipopolysaccharide effect on plasma hyaluronan level. Taken together with earlier results from our laboratory, these data indicate that: (a) Kupffer cell activation by lipopolysaccharide results in suppression of hyaluronan uptake by sinusoidal endothelial cells and (b) such modulation of endothelial cell function is likely mediated by products of the lipoxygenase pathway of arachidonate metabolism. (Hepatology 1994;19:464-470).
Endotoxin-induced cytokine gene expression and excretion in the liver
Authors: Luster Michael I. , Germolec Dori R. , Yoshida Takahiko , Kayama Fujio , Thompson Morrow
Published: March 2007

Peptide mediators, including tumor necrosis factor-α, interleukin 1 and interleukin-6, are associated with many chronic inflammatory diseases and septic shock. As such, considerable information has been collected by means of study of cytokine secretion from isolated cells or plasma cytokines during septic shock or inflammatory disorders. In this investigation, we used semiquantitative polymerase chain reaction analysis and a recently developed liver slice model to examine the characteristics of cytokine profiles that occur in the liver, the main organ involved in endotoxemia, after lipopolysaccharide challenge. Tumor necrosis factor-α, interleukin-1α and interleukin-6 were rapidly secreted after in vivo LPS exposure or when added in vitro to rodent or human liver slice samples. This increase was associated with increased cytokine-specific mRNA transcripts. Kinetic analysis revealed that most tumor necrosis factor-α is released from the liver within 1 hr of lipopolysaccharide challenge, whereas interleukin-1α and interleukin-6 continued to be produced for the entire culture period. Addition of monoclonal antibodies against tumor necrosis factor-α or interleukin-1α to the culture partly inhibited interleukin-6 secretion, indicating that interleukin-1α and tumor necrosis factor-α help mediate and sustain interleukin-6 synthesis. Depletion of hepatic sinusoidal macrophages (Kupffer cells) by a liposome-mediated macrophage “suicide” technique indicated that almost all of the secreted interleukin-1α and tumor necrosis factor-α originate from these cells, whereas interleukin-6 secretion might also include other cell types. This study supports and extends previous findings and allows for a more rational approach to developing effective therapies against chronic inflammatory diseases and septic shock. (Hepatology 1994;19:480-488).
In vivo response of hepatocytes to growth factors requires an initial priming stimulus
Authors: Webber Eric M. , Godowski Paul J. , Fausto Nelson
Published: March 2007

Although growth factor effects have been studied in cultured hepatocytes, little information exists as to whether these factors can trigger hepatocyte replication in vivo. In this study we infused epidermal growth factor, transforming growth factor-α and hepatocyte growth factor directly into the portal vein of rats for 24 hr to see whether they could induce DNA synthesis in normal livers or in livers subjected to one-third hepatectomy. Infusion of transforming growth factor-α or epidermal growth factor at doses up to 80 μg/24 hr had little effect on hepatic DNA synthesis in normal liver, whereas the monomeric and heterodimeric forms of hepatocyte growth factor generally produced increases of less than threefold in hepatic DNA synthesis. In contrast, after one-third hepatectomy infusion of epidermal growth factor, transforming growth factor-α or hepatocyte growth factor produced dose-dependent increases in hepatic DNA synthesis. At a dose of 40 μg/24 hr, epidermal growth factor increased DNA synthesis threefold, whereas transforming growth factor-α or hepatocyte growth factor increased DNA synthesis to greater than six times that in rats that had undergone hepatectomy alone. Furthermore, infusion of these growth factors, with or without one third-hepatectomy, induced the expression of transforming growth factor-α mRNA in the liver. The pattern of protooncogene expression induced by one-third hepatectomy was studied to determine the effect of this procedure in sensitizing the liver to the growth factors. Compared with the well-characterized two-thirds hepatectomy system, there was a similar but smaller increase in c-myc expression but no induction of c-jun expression. The results suggest that a small functional deficit in the liver that by itself causes little DNA synthesis “primes” hepatocytes for replication and that the loss of liver mass and growth factor infusions complement each other by providing essential stimuli needed for DNA synthesis. (Hepatology 1994;14:489-497).
Acetaldehyde activates the promoter of the mouse α2(I) collagen gene
Authors: Parés,* Albert , Potter James J. , Rennie Lynda , Mezey Esteban
Published: March 2007

The mechanism whereby ethanol ingestion results in hepatic fibrosis remains unknown. Acetaldehyde has been shown to increase α1(I) collagen gene transcription in human fibroblasts and in rat myofibroblastlike cells (Ito cells) in culture. In this study, the effect of acetaldehyde was determined on the activation of the α2(I) collagen promoter. A plasmid containing the mouse α2(I) collagen promoter region (−2000 to 54), fused to the coding sequence of the reporter gene chloramphenicol acetyl transferase and similar plasmid constructs containing deletions in the collagen promoter, were transfected into NIH 3T3 fibroblasts in culture. Acetaldehyde (200 μmol/L) and transforming growth factor-β1 (5 ng/ml) activated the wild type promoter. The combination of acetaldehyde and transforming growth factor-β1 did not result in a greater effect than either alone. Acetaldehyde inhibited, whereas transforming growth factor-β1 did not activate, the promoter, with a −352 to −104 deletion. By contrast, acetaldehyde had no effect, whereas transforming growth factor-β1 resulted in a small decrease in the activity of the promoter, with a −501 to −352 deletion. This study shows that acetaldehyde and transforming growth factor-β1 independently activate the mouse α2(I) collagen promoter and that this activation is mediated by the same proximal region of the promoter. (Hepatology 1994;19:498-503).
Liver transplantation for Wilson’s disease: Indications and outcome
Authors: Schilsky Michael L. , Scheinberg Herbert I. , Sternlieb Irmin
Published: March 2007

The objective of this study was to determine the indications for and results of liver transplantation in patients with Wilson’s disease on the basis of results of a survey with retrospective review of data obtained on 55 transplants performed at centers in the United States and Europe. The study group comprised 32 females and 23 males, aged 8.5 to 51 yr, with features diagnostic of Wilson’s disease. Indication for orthotopic liver transplantation included hepatic insufficiency (n = 32), wilsonian fulminant hepatitis (n = 21), intractable neurological Wilson’s disease (n = 1) and gastrointestinal hemorrhage (n = 1). Forty-three patients have survived, at this writing, from 3 mo to 20 yr. Mean and median survival after orthotopic liver transplantation were 2.7 and 2.5 yr, respectively. Survival at 1 yr was 79. Nonfatal complications occurred in five patients. Of the seven patients given transplants for hepatic insufficiency who manifested neurological and/or psychiatric manifestations at the time of orthotopic liver transplantation, four showed improvement of these symptoms. One patient given a transplant for intractable neurological disease improved but died of a vascular complication. Our data demonstrate that liver transplantation is life-saving but not without risk for patients with wilsonian fulminant hepatitis or chronic severe hepatic insufficiency unresponsive to medical therapy. Furthermore, neurological or psychiatric symptoms due to Wilson’s disease may improve after liver transplantation; however, the role of this procedure in the management of patients with neurological Wilson’s disease in the absence of hepatic insufficiency is still uncertain. (Hepatology 1994;19:583-587).
Endothelial activation and circulating vascular adhesion molecules in alcoholic liver disease
Authors: Adams David H. , Burra Patrizia , Hubscher Stefan G. , Elias Elwyn , Newman Walter
Published: March 2007

Alcoholic hepatitis is characterized by hepatocyte necrosis associated with infiltration of the liver parenchyma by neutrophils. The mechanisms responsible for recruiting neutrophils to the liver are unknown. We report high circulating levels and tissue expression of the endothelial adhesion molecule E-selectin in alcoholic hepatitis. Because expression of E-selectin is involved in neutrophil transmigration into inflamed tissue, it may play a crucial role in the recruitment of neutrophils to the liver in alcoholic hepatitis. By contrast, we detected high levels of vascular cell adhesion molecule-1, the endothelial counter-receptor for the lymphocyte adhesion molecule very late antigen-4, in alcoholic cirrhosis, which is associated with a predominantly mononuclear cell infiltrate. Both diseases were associated with high levels of circulating intercellular adhesion molecule-1, which is released by activated lymphocytes, providing further evidence of immune activation in alcoholic liver disease. (Hepatology 1994;19:588-594).
Pathogenesis of glucose intolerance and diabetes mellitus in cirrhosis†
Authors: Petrides Alexander S. , Vogt Christoph , Schulze-Berge Dirk , Matthews Dwight , Strohmeyer Georg
Published: March 2007

Glucose intolerance and diabetes mellitus are both prevalent in cirrhosis, yet the pathogenesis of impaired glucose metabolism remains unknown. Therefore insulin secretion (hyperglycemic clamp, +125 mg/dl), insulin sensitivity (euglycemic hyperinsulinemic insulin clamp, +10 μU/ml and +50 μ/ml), whole-body glucose oxidation (indirect calorimetry) and glucose turnover ([6,6-2H2]glucose isotope dilution) were evaluated in a homogenous group of cirrhotic patients with glucose intolerance (n = 7) or frank diabetes mellitus (n = 6). The results were compared with those obtained in control subjects (n = 8). In glucose-intolerant patients, whole-body glucose uptake (mainly reflecting glucose utilization by muscle) was significantly impaired in patients during both insulin infusions as a result of decreased stimulation of the two major intracellular pathways of glucose disposal-nonoxidative glucose disposal (i.e., glycogen synthesis) and glucose oxidation. Hepatic glucose production was normal in the basal state and was normally suppressed during stepwise insulin infusion (by 65% and 85%, respectively, p = NS vs. controls). Hyperglycemia-induced increases of plasma C-peptide concentrations were comparable to those in controls (p = NS). In diabetic patients, insulin-mediated glucose uptake was significantly reduced, mainly because of impaired non-oxidative glucose disposal. Glucose oxidation appeared to be reduced, too. Hepatic glucose production was significantly increased in the basal state (3.03 ± 0.24 vs. 2.34 ± 0.10 mg/kg min, p < 0.02) and during insulin infusion ( +50 μ/ml: 0.67 ± 0.17 vs. 0.13 ± 0.08 mg/kg min, p < 0.05) compared with that in controls. Both the first and second phases of β-cell secretion were significantly reduced in response to steady-state hyperglycemia (both p < 0.01 vs. control values). In conclusion, glucose intolerance in cirrhosis results from two abnormalities that occur simultaneously: (a) insulin resistance of muscle and (b) an inadequate response (even when comparable to that of controls) of the β-cells to appropriately secrete insulin to overcome the defect in insulin action. Diabetes mellitus in insulinresistant cirrhotic patients develops as the result of progressive impairment in insulin secretion together with the development of hepatic insulin resistance leading to fasting hyperglycemia and a diabetic glucose tolerance profile. (Hepatology 1994;19:616-627).
Characterization of a chicken hepatoma cell line with a specific defect in fibrinogen secretion
Authors: Oddoux Carole , Grieninger Gerd
Published: March 2007

This study characterizes plasma protein synthesis and its hormonal regulation in a chicken hepatoma cell line, with particular emphasis on fibrinogen. Whereas virtually all aspects of hemopexin, transferrin and albumin production in these cells corresponded to those of cultured primary hepatocytes, fibrinogen was not secreted. Analysis of fibrinogen subunit synthesis revealed a specific defect in synthesis of one subunit, γ, correlating with a lack of its mRNA. Pulse-chase and electron microscopic studies demonstrate that, despite the inability of these cells to secrete the Aα and Bβ subunits produced, there is no long-term accumulation of unsecreted fibrinogen. The Bβ fibrinogen subunits are largely degraded 2 hr after synthesis. During this time, approximately half of the Aα subunits are degraded; the rest are converted to the glycosylated form. The implications of this type of defect with respect to the pathogenesis of fibrinogen storage disease are discussed. (Hepatology 1994;19:682-687).
Fibrinogen assembly: Insights from chicken hepatocytes
Authors: Oddoux Carole , Grieninger Gerd
Published: March 2007

In all vertebrate species studied, the complex, disulfide-linked structure of fibrinogen is essentially the same: a hexamer assembled from three different subunits (Aα, Bβ,γ)2. This study utilized species differences in fibrinogen subunit monomer pools to address the question of how these surplus subunit pools may affect the assembly process. We used a chicken model system in which Bβ and γ-subunits are present in excess, in contrast to the Aα and γ-subunit surplus found in human model systems. Analysis was based on pulse-chase experiments with electrophoretic separation of intracellular forms and secreted fibrinogen on reducing and nonreducing gels. The chicken liver-derived cells employed for this purpose, primary hepatocytes and a hepatoma cell line with a fortuitous defect in fibrinogen synthesis, together offer advantages over human systems for resolving the complexes formed in the early stages of assembly. The results demonstrate that in chicken hepatocytes there is an initial binding of γ to Aα subunits rather than to Bβ subunits, as occurs in human hepatoma cells. Nevertheless, the presence of similar intracellular fibrinogen-related forms in both chicken- and human-derived cells, in the context of their differing subunit monomer pools, suggests an assembly pathway common to both species, with the versatility to be regulated by limitation of Aα or Bβ subunit production. (Hepatology 1994;19:688-693).
Effect of dietary phospholipids and their constituents on bile composition in rats and hamsters†
Authors: Peled Yochanan , Gilat Tuvia
Published: March 2007

The formation of cholesterol gallstones is a result of an interaction between bile lipid concentration, composition and other factors. The solubilization of cholesterol in bile is affected by the nature of the fatty acids and head groups of biliary phospholipids. In this study we tried to modulate the composition of biliary lipids in the rat and hamster by means of dietary supplementation of whole phospholipids or their constituents (at 3% to 5% of food weight). A striking effect of ethanolamine feeding in rats and hamsters was demonstrated: Biliary cholesterol concentration and cholesterol saturation index were significantly lower (p < 0.03). In rats, bile acid concentration was increased, contributing to decreased bile lithogenicity. Ethanolamine also increased biliary phospholipid output. Other test substances had less marked effects. The addition of lecithin to rat diet significantly increased phospholipid concentration (p < 0.05) compared with controls. Cholesterol and bile acid concentrations were reduced in palmitic acid-fed hamsters (NS). Choline supplementation insignificantly increased the cholesterol saturation index in hamsters. Despite the clear effect of ethanolamine on biliary lipid composition, no change could be demonstrated in the proportion of phosphatidylethanolamine in bile. It is postulated that ethanolamine was methylated in the liver to choline. Our data demonstrate that biliary lipid composition can be modulated by dietary phospholipids or their components. (Hepatology 1994;19:708-713).
Deficiency of bile acid transport and synthesis in oval cells from carcinogen-fed rats
Authors: Blumrich Matthias , Pack Renate , Oesch Franz , Petzinger Ernst , Steinberg Pablo
Published: March 2007

Freshly isolated oval cells, which we obtained from the livers of rats fed a choline-deficient/DL-ethioninesupplemented diet, did not transport bile acids. Compared with freshly isolated rat hepatocytes they took up only negligible amounts of [3H]taurocholate or [14C]cholate. The cells bound small amounts of radioactive bile acids. This portion of the total cell-associated radioactivity was enhanced on membrane permeabilization. In contrast to cultured liver parenchymal cells from untreated rats, no bile acid synthesis was detected in cultured oval cells. Cultured oval cells also lost the ability to conjugate exogenously added cholate (100 μmol/L) with taurine or glycine. However, when liver parenchymal cells were isolated from carcinogen-fed rats, bile acid uptake was diminished compared with that in hepatocytes from control animals. In particular, the maximum values of taurocholate and cholate uptake were decreased by 75 and 50, respectively, whereas the Michaelis-Menten constant values were not altered. The study demonstrates that (a) oval cells lack typical liver parenchymal cell-specific properties such as bile acid uptake, bile acid synthesis and conjugation of bile acids with taurine/glycine and therefore do not contribute to bile acid dependent bile formation (b) proliferating in livers of rats fed a choline-deficient/DL-ethionine-supplemented diet are part of the bile duct epithelial cell compartment); and (c) bile acid uptake is reduced in liver parenchymal cells of rats fed a choline deficient/DL-ethionine-supplemented diet, and this effect is due to a decrease in transport capacity without a decrease in transport affinity. (Hepatology 1994;19:722-727).
111Indium labeling of hepatocytes for analysis of short-term biodistribution of transplanted cells
Authors: Gupta Sanjeev , Lee Chang-Don , Vemuru Ravikumar P. , Bhargava Kuldeep K.
Published: March 2007

Hepatocyte transplantation is useful for ex vivo gene therapy and liver repopulation. Methods for hepatic reconstitution have recently been developed but optimization of hepatocyte transplantation systems is necessary. To develop systems for noninvasive assessment of the biodistribution of transplanted cells, we labeled hepatocytes with 111indium-oxine. Our initial studies showed that hepatocytes incorporated 111indium-oxine with an efficiency of approximately 20%. After labeling, cell viability was unchanged and 111indium was present in hepatocytes after overnight culture, as well as after intrasplenic transplantation. Transplanted cells were successfully localized by means of scintigraphic imaging. The scintigraphic patterns of cell distribution were different when hepatocytes were transplanted by means of either spleen or internal jugular vein, which deposit cells into separate vascular beds. Quantitative analysis of the biodistribution of 111indium-labeled hepatocytes indicated that within 2 hr of intrasplenic transplantation, cells were predominantly localized in liver and spleen, and occasionally in lungs. To determine whether the rate of intrasplenic cell injection influenced translocation of hepatocytes, we transplanted cells in normal rats. Despite intrasplenic cell injection at a variety of rates, organ-specific distribution of 111indium-labeled hepatocytes remained unchanged. Labeling with 111indium did not affect long-term survival of transplanted hepatocytes. These results indicate that 111indium-labeling of hepatocytes should greatly assist noninvasive analysis in the short-term of the biodistribution of transplanted hepatocytes. (Hepatology 1994;19:750-757).
Blood-to-lymph migration of small lymphocytes through the liver of the sheep
Authors: Young Alan J. , Hare Gregory M. T. , Hay John B.
Published: March 2007

The process of lymphocyte migration is required for the systemic dissemination of immunological memory and immune surveillance. We report here experiments to quantitate the normal traffic of lymphocytes that occurs from blood to lymph through the liver and hepatic node in the sheep. Comparisons were made with known lymphocyte homing pools. Individual afferent hepatic lymphatics had cell outputs of 1.4 ± 0.1×106 cells/hr, suggesting that the total combined lymphocyte output from the liver was no greater than about 1×107 cells/hr. The lymphocyte output in efferent hepatic lymph was 6.2 ± 0.4×107 cells/hr, comparable to the cell outputs recorded from other lymph nodes of similar size. When the specificity of lymphocytes homing through the liver or hepatic node was examined, we found similarities to both the peripheral lymph node and intestinal lymph node homing patterns. Migration into afferent hepatic lymph was found to be different from that into intestinal or subcutaneous efferent lymph, and the kinetics of migration into hepatic afferent lymph was faster than that observed into efferent compartments. Intravenously injected endotoxin was found to alter the normal lymph flow through the liver tissue and the hepatic node; it appeared to enhance the migration of macrophages out of the liver by way of the afferent lymph. These studies suggest unique features of lymphocyte traffic through the liver and the need for further experiments on hepatic lymphocyte traffic, particularly in pathological states with substantial mononuclear cell infiltration. (Hepatology 1994;19:758-763).
Artificial bile inhibits bile salt-induced gallbladder glycoprotein release in vitro
Authors: O’Leary Daniel P.
Published: March 2007

The more hydrophobic bile salts cause rapid release of preformed gallbladder mucin and other glycoproteins by gallbladder explants in vitro, whereas the less hydrophobic bile salts elicit a lesser response. This study was designed to determine (a) whether this short-term effect was matched by a sustained increase in glycoprotein secretion over 24 hr and (b) whether it occurred when bile salts were presented in model biles rather than aqueous solution. Although 3 mmol/L taurodeoxycholate in aqueous solution increased release of preformed gallbladder glycoprotein to 843 of control values after 30 min incubation (p < 0.001), no significant increase was observed after 24 hr. The more prolonged exposure also reduced precursor uptake by 32 (p < 0.05) and inhibited synthesis of new glycoprotein by 24 (p < 0.05). Moreover, the stimulatory effect of taurodeoxycholate on release of gallbladder glycoprotein was much reduced when it was presented in model biles rather than in aqueous solution. Nor was there any difference between the effects of more hydrophobic vs. less hydrophobic bile salts when presented in model biles. Aqueous solutions of the more hydrophobic bile salts induce a rapid release of gallbladder glycoprotein in vitro but do not produce a sustained increase in glycoprotein secretion. Their effect is liable to be prevented in vivo by interaction between bile salts and the other lipids in gallbladder bile. (Hepatology 1994;19:771-774).
Nontransplant options for the treatment of metabolic liver disease: Saving livers while saving lives
Authors: Balistreri William F.
Published: March 2007

“When medicine has really succeeded brilliantly in technology, as in immunization or endocrine-replacement therapy, so that the therapeutic measures can be directed straight at the underlying disease mechanism and are decisively effective, the cost is likely to be very low indeed. It is when our technologies have to be applied halfway along against the progress of disease, or must be brought in after the fact to shore up the loss of destroyed tissue, that health care becomes enormously expensive. The deeper our understanding of a disease mechanism, the greater are our chances of devising direct and decisive measures to prevent disease, or to turn it around before it is too late.” Lewis Thomas (1).
Just say “no” to viral hepatitis?
Authors: Chung Raymond T.
Published: March 2007

Interferons (IFNs) induce antiviral activity in many cell types. The ability of IFN-γ to inhibit replication of ectromelia, vaccinia, and herpes simplex-1 viruses in mouse macrophages correlated with the cells’ production of nitric oxide (NO). Viral replication was restored in IFN-γ-treated macrophages exposed to inhibitors of NO synthase. Conversely, epithelial cells with no detectable NO synthesis restricted viral replication when transfected with a complementary DNA encoding inducible NO synthase or treated with organic compounds that generate NO. In mice, an inhibitor of NO synthase converted resolving ectromelia virus infection into fulminant mousepox. Thus, induction of NO synthase can be necessary and sufficient for a substantial antiviral effect of IFN-γ.