bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenic role of hepatitis B virus in hepatitis B surface antigen—negative decompensated cirrhosis
Authors: Chung Hau-Tim , Lai Ching-Lung , Lok Anna S. F.
Published: March 2007

This study was conducted to determine the rate of detection of serum hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg)-negative decompensated cirrhotic patients who had hepatitis B core and/or surface antibodies (anti-HBc and/or anti-HBs), and to compare the outcome of HBsAg-positive cirrhotic patients who did or did not clear HBsAg during follow-up. Six (5%) of 121 HBsAg-positive cirrhotic patients lost HBsAg after 0.2 to 17.1 years (mean, 9.1 ± 6.2 yr) of follow-up. The cumulative rates of loss of HBsAg at 1, 5, 10, and 15 years were, respectively, 1.3%, 1.3%, 7.4%, and 44.5%. Compared with the patients who remained HBsAg-positive, those who lost HBsAg had milder disease at presentation and significantly longer survival. Of the patients who lost HBsAg, 83% had improvement in liver function after the loss of HBsAg, and all were alive at the time of writing (0.8 to 5.7 years after loss of HBsAg), whereas 27% of those who remained HBsAg-positive had died and 29% had deterioration in liver function. The rate of detection of serum HBV DNA by polymerase chain reaction (PCR) assay was higher in HBsAg-positive cirrhotic patients who lost HBsAg: 67% versus cirrhotic patients who had no previous history of chronic HBV infection; 16% (cryptogenic) and 29% (hepatitis C virus and/or alcohol-induced liver disease). In summary, we found that using PCR, serum HBV DNA can be detected in 28% of HBsAg-negative cirrhotic patients who were studied, but the pathogenic significance of such small amounts of virus is not clear. Liver function can improve and survival can be prolonged in HBsAg positive decompensated cirrhotic patients who subsequently lost HBsAg. (Hepatology 1995;22:25-29.)
Naturally occurring hepatitis B virus core gene mutations
Authors: Akarca Ulus S. , Lok Anna S. F.
Published: March 2007

Mutations in the hepatitis B virus (HBV) core gene may influence disease activity by altering immune recognition sites or level of virus replication. Sera from 69 Chinese patients with chronic HBV infection were analyzed by direct sequencing of polymerase chain reaction amplification of HBV DNA to determine the frequency and location of naturally occurring HBV core gene mutations. All but one patient had nucleotide changes, and 44 (64%) patients had at least one amino acid change (mean, 3.7; range, 1-13) when compared with published sequences. Multiple regression analysis showed that the frequency of core gene mutations was significantly associated with precore stop-codon mutation, hepatitis B e antigen negativity, and active liver disease, but not patients' age. The mean number of amino acid changes/patient for hepatitis B e antigen (HBeAg)-positive patients with elevated versus normal aminotransferase levels were, respectively, 2.8 ± 0.4 and 0.6 ± 0.2. The corresponding values for HBeAg-negative patients were, respectively, 5.0 ± 1.2 and 6.0 ± 1.5. Thirteen patients were serially studied, the mean rates of amino acid substitution in HBeAg-positive patients who did or did not clear HBeAg during follow-up were 5.7 ± 0.8 and 0 per codon/yr. Most of the mutations were clustered in the middle of the core gene that harbor several major B- and helper T-cell epitopes. Very few mutations were found in the C-terminal part of the core gene. In summary, mutations in the core gene can be frequently detected in patients with chronic HBV infection. These mutations occur predominantly around the time of HBeAg clearance when liver disease is most active. (Hepatology 1995; 22:50-60).
Proton spectroscopy of brain glutamine in acute liver failure
Authors: McConnell James R. , Antonson Dean L. , Ong Chin Siong , Chu Wei-Kom , Fox Ira J. , Heffron Thomas G. , Langnas Alan N. , Shaw Byers W.
Published: March 2007

Evidence indicates that the accumulation of glutamine in the brain plays an important role in the pathogenesis and severity of the encephalopathy of acute liver failure (ALF). This study uses in vivo proton magnetic resonance spectroscopy (<1>H MRS) to assess brain glutamine (GLN) in five cases of acute liver failure. The findings are consistent with prior investigations and suggest that the alpha <1>H of the GLN molecule can be used for noninvasive spectroscopic quantitation of brain GLN in patients with ALF. (Hepatology 1995;22:69-74.)
Intrahepatic cholangiographic appearance simulating primary sclerosing cholangitis in several hepatobiliary diseases: A postmortem cholangiographic and histopathological study in 154 livers at autopsy
Authors: Terada Tadashi , Nakanuma Yasuni
Published: March 2007

Intrahepatic cholangiography of primary sclerosing cholangitis (PSC) is characterized by stricture with or without dilation of the biliary tree. To evaluate whether this cholangiographic appearance is present in non-PSC livers as well as the histological features seen in non-PSC livers with this cholangiographic appearance, we performed postmortem intrahepatic cholangiography in 154 liver autopsy specimens. The PSC-like cholangiographic appearance was frequently found in cirrhosis with or without hepatocellular carcinoma (4 of 6, 67%), hepatocellular carcinoma (1 of 1,100%), adult-type polycystic disease of the liver and kidneys (2 of 3,67%), submassive hepatic necrosis (2 of 5, 40%), amyloidosis (1 of 2, 50%), and intrahepatic extensive thrombosis (1 of 1, 100%). It was also found but at lower frequency in metastatic carcinomas (3 of 13,23%) and leukemia/lymphoma infiltration (2 of 12, 17%). Histologically, in livers with such a PSC-like cholangiographic appearance, the intrahepatic bile ducts were compressed by fibrosis, inflammatory infiltrates, liver cysts, cancer cell infiltration, amyloid deposition, or portal thrombi. Dilated ducts had less pronounced changes than strictured ducts. In these hepatobiliary diseases, the changes of intrahepatic bile ducts in the livers without the PSC-like cholangiographic appearance were much less marked than those in the livers with it. These data suggest that the PSC-like intrahepatic cholangiographic appearance is present in several hepatobiliary diseases and that clinicians should take such diseases into consideration if stricture with or without dilation is found on intrahepatic cholangiography. (Hepatology 1995;22:75-81).
Effects of ursodeoxycholic acid and chenodeoxycholic acid on human hepatocytes in primary culture
Authors: Hillaire Sophie , Ballet François , Franco Dominique , Setchell Kenneth D. R. , Poupon Raoul
Published: March 2007

Hepatic bile acid concentrations are elevated in chronic cholestasis because of reduced canalicular excretion and active ileal absorption of the fraction eliminated in the gut. Ursodeoxycholic acid (UDCA) reduces the intestinal absorption of endogenous bile acids, thereby diminishing the concentrations to which liver cells are exposed. In the isolated perfused liver (in which vectorial bile acid transport is maintained), UDCA reduces the cytotoxic and cholestatic effects of endogenous bile acids. As a result, it has been suggested that UDCA or one of its conjugates could have a direct protective effect on hepatocyte structure and function. We therefore studied the effects of chenodeoxycholic acid (CDCA) and tauroursodeoxycholic acid (TUDCA) alone and in combination on the viability and certain functions of human hepatocytes in primary culture. TUDCA did not affect intracellular concentrations of CDCA when added concomitantly. In other experiments, CDCA (100 to 500 μmol/L) induced concentration-dependent increases in lactate dehydrogenase (LDH) leakage and decreases in cellular protein synthesis and albumin secretion. Neither TUDCA nor UDCA had similar effects at the same concentrations, nor did they have a protective effect when added concomitantly with CDCA at equimolar or twice-equimolar concentrations. These results suggest that UDCA has no direct cytoprotective effect when the bile acid concentrations to which human hepatocytes are exposed are unchanged. They also suggest that the hepatoprotective effect of UDCA in cholestatic human liver diseases and in the isolated perfused liver loaded with hydrophobic bile acids occurs through its effect on intestinal and hepatocyte transport systems. (Hepatology 1995;22:82-87.)
Noninvasive 24-hour ambulatory arterial blood pressure monitoring in cirrhosis
Authors: Møller Søren , Wiinberg Niels , Henriksen Jens H.
Published: March 2007

Cirrhotic patients have disturbed systemic hemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulant device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the daytime, SBP, DBP, and MAP were significantly lower in the patients than in the controls (median 118 vs. 127; 70 vs. 78; 86 vs. 94 mm Hg, P < .0001 to P < .05). The nighttime blood pressures were almost similar in the two groups (108 vs. 110; 65 vs. 67; 78 vs. 82 mm Hg, NS). Conversely, HR was significantly higher in the patients both in the daytime (86 vs. 72/min, P < .0001) and at night (80 vs. 64/min, P < .0001). Consequently, the reduction in blood pressure and HR from daytime to nighttime was significantly lower in the patients than in the controls (P < .0001 to P < .01). Multiple regression analysis showed HR, serum albumin, serum sodium, and clotting factors 2, 7, and 10 as significant independent predictors of SBP in cirrhosis. In conclusion, cirrhotic patients have elevated HR, but surprisingly normal arterial blood pressure during the nighttime, and the circadian variation in blood pressure and HR is diminished, probably because of an almost unaltered cardiac output during the 24 hours. These results may reflect a major defect in the ability of optimal regulation of blood pressure in cirrhotic patients. (Hepatology 1995; 22:88-95.)
Pathomorphologic characteristics of small hepatocellular carcinoma: A special reference to small hepatocellular carcinoma with indistinct margins
Authors: Nakashima Osamu , Sugihara Shigetaka , Kage Masayoshi , Kojiro Masamici
Published: March 2007

Some surgically resected small hepatocellular carcinoma (HCC) up to 2 cm in diameter have indistinct margins, and it is sometimes difficult to identify the margins of the cancer nodule in the resected specimen. We classified such tumors as small HCC with indistinct margins and carried out a morphological study to define their characteristics in comparison with small HCC with distinct margins as a control group. We have encountered 27 examples among 86 tumors smaller than 2.0 cm in diameter. The tumors of this type indistinctly retained the basic architecture of the background and were vaguely demarcated. Most tumors were uniformly composed of well-differentiated cancer tissue, which is characterized by increased cell density with increased nuclear/cytoplasm ratio, increased cytoplasmic eosinophilia, and irregular thin-trabecular pattern with occasional pseudoglandular pattern. Portal tracts were included within the cancerous tissue. There was a “replacing” growth pattern at the tumor/nontumor boundary. Four of the 27 lesions had a nodule-in-nodule appearance, and the inner nodules consisted of moderately differentiated HCC without portal tracts. In all of the small HCC with indistinct margins, tumor invasion into the portal vein and intrahepatic metastasis were not found. In a control group, the tumors were well-demarcated, and 53% of them were encapsulated. They were well-differentiated in 9, moderately differentiated in 38 and mixed well and moderately in 12. Tumor invasion into the portal vein and intrahepatic metastasis was found in 16 (27.1%) and 6 (10.2%), respectively. According to the above results, it is suggested that many HCCs arise as a tumor of the well-differentiated type containing portal tracts in a form of small HCC with indistinct margins. (Hepatology 1995; 22:101-105.)
Metabolic effect of sodium selenite: Insulin-like inhibition of glucagon-stimulated glycogenolysis in the isolated perfused rat liver
Authors: Roden Michael , Prskavec Martin , Fürnsinn Clemens , Elmadfa Ibrahim , König Jürgen , Schneider Barbara , Wagner Oswald , Waldhäusl Werner
Published: March 2007

Selenium, an essential trace element, has been shown to decrease plasma glucose concentrations of diabetic rats. To study the short-term effects of selenium on hepatic carbohydrate metabolism, isolated perfused livers of fed Sprague-Dawley rats were continuously infused with sodium selenite for 90 minutes. This resulted in an immediate elevation of selenium in the effluent perfusate (3.3 ± 0.1, 16.1 ± 0.4, 30.3 ± 1.6, and 118.9 ± 0.8 μmol/L at infusion of 10,50, 100, and 500 μmol/L sodium selenite, respectively). Basal hepatic glucose production decreased in a dose-dependent manner within 60 minutes of low-dose sodium selenite infusion (10: 0.60 ± 0.20, 50: 0.21 ± 0.40, and 100 ümol/L: 0.21 ± 0.09 μmol/L · min−1 · g−1 liver; P < .05 vs. zero time), while it was transiently increased by 500 μmol/L sodium selenite (1.11 ± 0.18 μmol · min<1> · g−1 liver; P < .05). Glucagon-stimulated glycogenolysis was suppressed by 50% (P < .05) at 1.8 nmol/ L insulin and by 90% (P < .001) at 10 μmol/L sodium selenite. That selenium concentration did not affect glutathione peroxidase activities in liver and perfusate erythrocytes within 60 minutes. Toxic effects of high-dose selenite (500 μmol/L), but not of low-dose selenite (10 μmol/L) infusion, were indicated by increased hepatic glucose (P < .05), lactate (P < .01), and lactate dehydrogenase (P < .001) release as well as histologically by degeneration and necrosis of periportal hepatocytes. In conclusion, low-dose selenite exerts a potent insulinlike effect on hepatic glycogenolysis in vitro by counteracting glucagon action, whereas high-dose selenite may severely impair liver function. (Hepatology 1995; 22:169-174.)
A morphological study of differentiated hepatocytes in vitro
Authors: Arterburn Linda M. , Zurlo Joanne , Yager James D. , Overton Regina M. , Heifetz Aaron H.
Published: March 2007

A problem traditionally encountered with primary hepatocyte cultures is their rapid dedifferentiation, which is reflected not only in decreased liver-specific functions, but also in dedifferentiated morphology: the cells flatten, depolarize, and lose many of the surface characteristics of normal hepatocytes in vivo. However, culture conditions that maintain primary rat hepatocytes in a healthy and highly differentiated state were recently developed: the hepatocytes are cultured in Chee's Medium supplemented with dexamethasone and dimethyl sulfoxide (DMSO) on collagen-coated Permanox dishes. In addition to retaining labile hepatocyte-specific functions (e.g., P450 activity and albumin synthesis), these hepatocytes also have a differentiated morphology. They have numerous microvilli and are cuboidal and cluster into cords reminiscent of hepatic trabeculae. Their subcellular organelles have normal morphology, and specialized junctions and bile canaliculi form within the membranes of adjacent cells. Actin fibers cluster at these canalicular surfaces. These hepatocytes also synthesize blood clotting factors, which aggregate into fibrin meshworks between cells. Taken together, these morphological data suggest that these hepatocytes are polarized and generally have an appearance very similar to parenchymal cells in the liver, and that the same culture conditions that promote retention of liver-specific functions are also critical to the maintenance of physiological morphology. In contrast to other hepatocyte cultures, this differentiated morphology, including the polarized nature of the cells, is established without the use of serum or flexible or complex extracellular matrices and shows a close link between cellular architecture and tissuespecific function. (Hepatology 1995; 21:175-187.)
Brefeldin a inhibits the transcytotic vesicular transport of horseradish peroxidase in intrahepatic bile ductules isolated from rat liver
Authors: Benedetti Antonio , Marucci Luca , Bassotti Cristina , Guidarelli Carlo , Jezequel Anne Marie
Published: March 2007

The fungal metabolite Brefeldin A (BFA) has become a valuable tool to address mechanisms of membrane transport in eukaryotic cells. The aim of the study was to investigate the action of BFA on the endocytic and transcytotic pathways in the biliary epithelium. Intrahepatic bile ductules were isolated from rat liver by collagenase digestion and mechanical separation of biliary tree from parenchymal tissue. Tissue remnants were first incubated in L-15 culture medium in absence or presence of BFA (10 or 20 μmol/L) or a BFA-inactive analog (B-36, 10 or 20 μmol/L) for 20 minutes at 37°C. They were then exposed to horseradish peroxidase (HRP) (10 mg/mL) for 3 minutes at 37°C and finally prepared for electron microscopy immediately (time 0) or after further 5,10, 15, 20, 60, or 120 minutes' incubation in HRP-free medium with or without BFA. In control cells, HRP was predominantly found in regularly shaped, spherical vesicles. In the presence of BFA but not of its analog, HRP was retained in a prominent tubular juxtanuclear network. Part of this network was labeled for thiamine pyrophosphatase (TPP), a Golgi enzyme marker. A morphometric analysis of HRP-containing structures was performed to quantify the intracellular distribution of HRP. In presence of BFA, the volume density (VD = % area) of HRP-containing structures in the basolateral region was not significantly different with respect to control cells at 0 (1.08 ± 0.11 vs. 1.32 ± 0.11) or 5 minutes, respectively (1.33 ± 0.19 vs. 1.40 ± 0.13). On the contrary, VD of HRP-containing structures in the apical region at 15 minutes decreased from 1.95 ± 0.19 in control cells to 1.12 ± 0.20 (P < .02) in BFA-treated cells. Most striking were the changes in VD of HRP-containing elements in the intermediate (juxtanuclear) area, showing a value of 0.45 ± 0.22 in control cells against 2.59 ± 0.50 in BFA-treated cells at 15 minutes (n = 10) (P < .01). Finally, taurocholic acid (TCA, 50 μmol/L) significantly increased the VD of HRP-labeled structures in the apical region only in the absence of BFA (2.22 ± 0.20, n = 5 vs. 1.14 ± 0.32 in BFA-treated samples at 5 minutes P < .02). These data suggest that in rat biliary epithelial cells, BFA does not interfere with fluid-phase endocytosis but inhibits the transcytotic vesicular pathway, as shown by the retention of HRP in the Golgi juxtanuclear area. These properties make BFA of interest for the study of intracellular mechanisms involved in bile ductular secretion. (Hepatology 1995; 22:194-201.)
Proliferation-associated differences in the spatial and temporal expression of gap junction genes in rat liver
Authors: Neveu Mark J. , Hully James R. , Babcock Karlee L. , Vaughan Jennifer , Hertzberg Elliot L. , Nicholson Bruce J. , Paul David L. , Pitot Henry C.
Published: March 2007

After a 70% partial hepatectomy (PH), the steady-state levels of Connexin (Cx)32, Cx26, and Cx43 messenger RNA (mRNA) transcripts each displayed unique patterns of temporal expression. Within 1 hour after surgical resection, increased expression of all three Cx mRNAs was observed. Subsequently, the level of Cx32 mRNA transcripts transiently decreased to a nadir at 12 hours. Comparisons of the spatial changes with previously reported hepatocyte proliferation kinetics induced by PH demonstrated that hepatocytes before Sphase “remodel” their GJs. Within 1 to 5 hours post-PH, midzonal hepatocytes exhibited diffuse membrane staining different from the normal punctate distribution. Subsequently, midzonal hepatocytes expressed colocalized punctate Cx32 and Cx26 immunostaining. Because the changes occurred in midzonal hepatocytes before 24 hours post-PH, near the peak of hepatocyte DNA synthesis, these findings indicate that Cx26 is enhanced in hepatocytes before the onset of S-phase. In contrast to the restricted expression of Cx43 in Glisson's capsule in adult liver, Cx43 protein and mRNA were enhanced specifically in proliferating bile duct and perisinusoidal cells post-PH. PH performed during continuous administration of 2-acetylaminofluorene (AAF) prevented changes in Cx32 and Cx26 staining observed in the absence of AAF. Proliferating oval cells were found to express diffuse Cx43 immunoreactivity. On day 11 post-PH and AAF, basophilic hepatocytes displayed both punctate Cx32 and Cx26 staining, whereas bile ducts and perisinusoidal cells expressed Cx43. These findings indicate that alterations in Cx32 and Cx26 expression occur rapidly in hepatocytes stimulated to proliferate and that several nonparenchymal liver cell types upregulate Cx43 expression when induced to proliferate. Differentiation of oval cells into basophilic hepatocytes resulted in their expression of Cx32 and Cx26. (Hepatology 1995; 22:202-212.)
Hepatic nitric oxide production following acute endotoxemia in rats is mediated by increased inducible nitric oxide synthase gene expression
Authors: Laskin Debra L. , Del Valle Marina Rodriguez , Heck Diane E. , Hwang Shaw-Min , Ohnishi Tsuyoshi S. , Durham Stephen K. , Goller Nancy L. , Laskin Jeffrey D.
Published: March 2007

In the present studies, we analyzed the effects of acute endotoxemia on hepatocyte nitric oxide production and functional activity. Treatment of rats with 5 mg/kg of lipopolysaccharide (LPS), which induces acute endotoxemia, caused an increase in nitric oxide production in the liver, as measured by electron paramagnetic spin trapping, which was evident within 6 hours. This was associated with expression of inducible nitric oxide synthase (iNOS) messenger (m) RNA in hepatocytes and in sinusoidal cells throughout the liver lobule. Acute endotoxemia also caused alterations in hepatic structure, including hypertrophy, vacuolization, and chromosomal emargination, however these changes were not apparent for 24 to 48 hours. Hepatocytes isolated from endotoxemic rats released increased amounts of nitric oxide, measured by nitrite production, in response to interferon gamma (γ-IFN) alone or in combination with LPS, tumor necrosis factor alpha, macrophage-colony stimulating factor, granulocyte/macrophage-colony stimulating factor, or hepatocyte growth factor. These results show that hepatocytes are sensitized by acute endotoxemia to respond to inflammatory mediators and growth factors. Increased nitrite production by hepatocytes was due to increased expression of iNOS mRNA and protein and was correlated with the time following induction of acute endotoxemia. Thus, cells isolated 48 hours after induction of acute endotoxemia released significantly more nitrite than cells recovered after 6 hours, a response that was not due to alterations in hepatocyte viability. Hepatocytes isolated from endotoxemic rats also exhibited a marked increase in proliferative capacity when compared with cells from control rats. Nitric oxide production by hepatocytes in vitro was associated with inhibition of cell growth and protein synthesis, which was reversed by the nitric oxide synthase inhibitor, NG-monomethyl-l-arginine (L-NMMA). Agarose gel electrophoresis showed extensive cytoplasmic DNA fragmentation in hepatocytes treated with LPS and γ-IFN, a characteristic of apoptosis, which was also reversed by L-NMMA. These results, together with our findings that treatment of rats with an inhibitor of nitric oxide synthase partially reversed the structural alterations in the liver associated with acute endotoxemia suggest that nitric oxide may contribute to the patho-physiologic response to this bacterially derived toxin. (Hepatology 1995; 22:223-234.)
Metabolism of cysteinyl leukotrienes in the perfused rat liver: The influence of endotoxin pretreatment and the cellular hydration state
Authors: Wettstein Matthias , Noé Birgitta , Häussinger Dieter
Published: March 2007

The influence of endotoxin on the hepatic metabolism and elimination of <3>H-leukotriene C4 (LTC4) and <3>H-leukotriene E4 was studied in the single-pass perfused rat liver. Endotoxin (4 mg/kg body mass) was injected intraperitoneally 8 to 10 hours before livers were isolated for perfusion. Tritiated leukotriene C4 and leukotriene E4 (10 nmol/L) were infused for 5 minutes, and metabolites in bile were determined by high-pressure liquid chromatography. In livers without endotoxin pretreatment, single-pass uptake of LTC4 was 77.3% ± 3.2%, and 73.8% ± 1.8% of the radioactivity taken up was excreted into the bile within 80 minutes. In endotoxin-pretreated livers, LTC4 uptake was 62.8% ± 3.5% and only 31.2% ± 1.5% of the radioactivity taken up was eliminated into the bile within 80 minutes. Bile flow was reduced to 0.20 ± 0.07 μL/g/min, compared with 1.18 ± 0.18 μL/g/min in untreated livers. Biliary excretion of infused <3>H-LTE4 was also reduced in endotoxin-pretreated livers (31.5% ± 6.1% compared with 61.4% ± 3.3% without endotoxin pretreatment), whereas uptake was not significantly different. The effect of cellular hydration state on leukotriene processing was also investigated. Anisoosmotic cell volume changes did not influence uptake and biliary excretion of <3>H-LTC4 and its metabolism in control livers. In endotoxin-pretreated livers, however, cell swelling induced by hypotonic perfusion media (225 mOsm/L) or by 3 mmol/L glutamine increased biliary elimination of the radioactivity taken up by 68% and 54%, respectively. Bile flow was also stimulated (0.31 ± 0.09 μL/g/min and 0.46 ± 0.01 μL/g/min, respectively). Colchicine (5 μmol/L) completely abolished the stimulatory effect of hypotonic perfusion on biliary leukotriene excretion. Hypertonic perfusion decreased leukotriene elimination into bile to 18.1% ± 3.8% of the radioactivity taken up and bile flow to 0.11 ± 0.04 μL/g/min. In livers perfused with hypertonic perfusion buffer, there was a higher amount of polar ω-oxidation metabolites detectable in bile compared with normotonic conditions. The data indicate that endotoxin impairs the canalicular excretion of cysteinyl leukotrienes, whereas there is only minor influence on uptake and intracellular metabolism. Cell swelling increases the biliary elimination of cysteinyl leukotrienes in endotoxin-treated livers, whereas cell shrinkage has the opposite effect, suggesting a modulatory role of cell volume in the canalicular transport of cysteinyl leukotrienes, at least in endotoxemia. Colchicine sensitivity of the cell volume effect suggests the involvement of a microtubule-dependent mechanism. (Hepatology 1995; 22:235-240.)
Sp1 binding activity increases in activated Ito cells
Authors: Rippe Richard A. , Almounajed Ghamen , Brenner David A.
Published: March 2007

Ito cells are the primary cell type in the liver responsible for increased type I collagen production observed during fibrogenesis. After a fibrogenic stimulus, Ito cells change from their normal quiescent state to an activated state. In this study, we examined the expression of the α1(I) collagen gene in Ito cells that were freshly isolated from normal rat liver (quiescent) and Ito cells that were activated by culture on plastic. Northern blots showed that α1(I) collagen messenger RNA levels were low in freshly isolated Ito cells and Ito cells cultured on plastic for up to 4 days, but were induced after 7 days in culture. To determine the location of important transcriptional regulatory elements within the 5′-flanking region of the α1(I) collagen gene, transient transfections using various portions of the α1(I) collagen gene promoter linked to the luciferase gene were performed in cultured Ito cells. As in fibroblast cells, only 220 base pairs (bp) of immediate 5′-flanking sequence of the collagen α1(I) gene was necessary for efficient expression of the reporter gene. Deoxyribonuclease I footprinting analysis and mobility shift assays showed dramatic differences in the DNA binding proteins that interact with the 220 base pair promoter region of the α1(I) collagen gene between freshly isolated and activated Ito cells. Sp1 binding activity was greatly increased in activated Ito cells, as was binding activity for CCAAT binding factor (CBF), a transcription factor previously shown to interact with the α2(I) collagen gene promoter. The increased Sp1 binding activity to the α1(I) collagen gene promoter involves a posttranscriptional event, as shown by Northern and Western blots. Therefore, we show that activated Ito cells have a different pattern of transcription factor binding activity interacting with the α1(I) collagen gene promoter compared with quiescent Ito cells, including increased Sp1 binding activity, and that this may contribute to the increase in α1(I) collagen gene expression during fibrosis. (Hepatology 1995; 22:241-251.)
Tumor necrosis factor-alpha modulates CCAAT/enhancer binding proteins-DNA binding activities and promotes hepatocyte-specific gene expression during liver regeneration
Authors: Diehl Anna Mae , Yang Shi Qi , Yin Ming , Lin Hui Zhi , Nelson Steve , Bagby Greg
Published: March 2007

Injury-related cytokines, such as tumor necrosis factor-alpha (TNF), may preserve liver-specific gene expression during the subsequent regenerative response by modulating the activity of transcription factors, including CCAAT/enhancer binding proteins (C/EBPs), which regulate differentiated gene expression in hepato-cytes. To test this theory, rats were treated with neutralizing antibody to TNF or nonimmune immunoglobulin before partial hepatectomy (PH) and regenerative changes in the messenger RNAs (mRNAs), proteins, and DNA-binding activities of C/EBP isoforms and the expression of a C/EBP-regulated gene, phosphoenol pyruvate carboxykinase (PEPCK), were compared. Before PH, the expressions of C/EBP-α, C/EBP-β, and C/EBP-γ were similar in the two treatment groups. Dimers containing C/EBP-α and C/EBP-β accounted for virtually all of the C/EBP DNA binding activity and mRNA for PEPCK, the rate limiting hepatocyte enzyme for gluconeogenesis, was barely detected. After PH, in control rats, mRNA and nuclear protein concentrations of C/EBP-β and C/EBP-γ increased approximately fivefold by 3 hours after PH. This was accompanied by increased DNA binding activity of these C/EBP isoforms and decreased DNA binding activity of C/EBP-α. mRNA levels of PEPCK, a gene that is strongly transactivated by non-α C/EBP isoforms, increased fivefold. Pretreatment with anti-TNF antibodies prevented regenerative induction of C/EBP β and γ expression and DNA-binding activity. The nature of dimers binding to C/EBP cis-acting elements remained similar to that observed in liver before PH and increases in PEPCK mRNA were blunted. These results support the theory that TNF helps maintain liver-specific gene expression during liver regeneration by altering transcription factor complexes that regulate differentiated gene expression in hepatocytes. (Hepatology 1995; 22:252-261.)
The role of Kupffer cells in the differentiation process of hepatic natural killer cells
Authors: Vanderkerken Karin , Bouwens Luc , Van Rooijen Nico , Van Den Berg Kit , Baekeland Marijke , Wisse Eddie
Published: March 2007

Pit cells, or hepatic natural killer (NK) cells, present in rat liver sinusoids, represent an organ-associated NK cell population, with a higher level of activation and a different morphology when compared with peripheral blood NK cells. These cells are the result of an influx of peripheral blood NK cells in the liver microenvironment, followed by an activation or differentiation process toward the highly activated phenotype. In this work we investigated the role of Kupffer cells in this differentiation process of NK cells in the liver sinusoids. In vivo elimination of Kupffer cells with the macrophage cytotoxic drug dichloromethylene diphosphonate induced a decrease in number of hepatic NK cells that paralleled that of Kupffer cells. This effect was further investigated in vitro. Kupffer cell-conditioned medium appeared to enhance the viability, tumor-cytotoxic activity, and adherence of hepatic NK cells to liver endothelial cells in vitro. We conclude therefore that Kupffer cells, present in the microenvironment of the liver sinusoids, play an essential role in the differentiation process of peripheral blood NK cells to the highly activated hepatic NK cell population. (Hepatology 1995; 22:283-290.)
Liver transplantation for sclerosing cholangitis
Authors: Narumi Shunji , Roberts John P. , Emond Jean C. , Lake John , Ascher Nancy L.
Published: March 2007

The clinical course of 37 patients who underwent 46 liver transplantations for primary (n = 33) and secondary (n = 4) sclerosing cholangitis was reviewed. The median follow-up was 37 months. The patient and graft survivals for patients with primary sclerosing cholangitis at 1, 2, and 5 years were 96.9%, 91.6%, 87.9%, and 83.1%, 74.2%, 65.2%, respectively. In the patients with primary sclerosing cholangitis (PSC), prior surgery except for simple cholecystectomy was associated with significantly greater operative time and blood loss. No cholangiocarcinoma was identified at the time of transplantation. Human leukocyte antigen typing for PSC patients was heavily weighed toward B8 (58.8%) compared with control (11.8%). Sixty-two percent of patients with PSC also had inflammatory bowel disease. Moderate or severe rejection requiring OKT3, “rescue therapy” with FK506, or retransplantation was relatively higher in patients with inflammatory bowel disease (70%) versus patients without inflammatory bowel disease (36.4%) and a matched control group (37.5%). Progressive inflammatory bowel disease was seen in 6 of 19 patients, with 3 developing cancer and a dysplasia. Two patients in the entire group died of sepsis and 3 of colon cancer (2 recurrent and 1 primary). These data demonstrate that excellent survival results can be achieved in this group of patients. Rejection is frequent and often severe and steroid refractory. Colon cancer represents the most frequent cause of death in PSC patients after liver transplantation and demands constant attention. (Hepatology 1995;22:451-457.)
Hemodynamics after orthotopic liver transplantation: Study of associated factors and long-term effects
Authors: Gadano Adrian , Hadengue Antoine , Widmann Jean Jacques , Vachiery Florence , Moreau Richard , Yang Song , Soupison Thierry , Sogni Philippe , Degott Claude , Durand François , Bernuau Jacques , Belghiti Jacques , Erlinger Serge , Benhamou Jean Pierre , Lebrec Didier
Published: March 2007

Among 68 liver transplant recipients, 190 hemodynamic studies were performed to evaluate the role of sepsis, anemia, acute graft rejection, and persistent portosystemic shunts. The hemodynamic outcome after orthotopic liver transplantation (OLT) in stable patients was also determined. Patients with sepsis showed a significant increase in cardiac index (5.1 ± 0.9 vs. 3.4 ± 0.7 L/min m2) and hepatic venous pressure gradient (6.3 ± 2.9 vs. 3.3 ± 2.1 mm Hg), compared with patients without sepsis. Cardiac index was higher in patients with, than in patients without, anemia (4.1 ± 0.6 vs. 3.0 ± 0.6 L/min m2). The hepatic venous pressure gradient was higher in patients with than in patients without acute graft rejection (5.1 ± 2.9 vs. 2.6 ± 1.2 mm Hg). Among patients with acute rejection, the hepatic venous pressure gradient was higher in patients with severe rejection than in those with moderate or mild rejection (7.2 ± 3.3 vs. 4.6 ± 2.4 and 2.8 ± 0.9 mm Hg). In the postoperative period, in patients undergoing transplantation for acute liver failure, the hepatic blood flow was normal and significantly lower than in patients receiving transplant for cirrhosis (1.15 ± 0.37 vs. 1.96 ± 0.71 L/min). In patients undergoing transplantation for cirrhosis, cardiac index, azygos, and hepatic blood flows significantly decreased after 1 year compared with the first 6 postoperative months. Multivariate analysis showed that sepsis, anemia, and time after OLT were independent variables influencing cardiac index. Sepsis, time after OLT, and the existence of portosystemic shunts were independent variables influencing hepatic blood flow. These results show that sepsis, anemia, acute graft rejection, and persistent portosystemic shunts induce modifications in hemodynamics in liver transplant recipients. Furthermore, in patients who undergo OLT for cirrhosis, the posttransplantation hyperdynamic syndrome tends to normalize with time. (Hepatology 1995; 22:458-465.)
Decreased right heart blood volume determined by magnetic resonance imaging: Evidence of central underfilling in cirrhosis
Authors: Møller Søren , Søndergaard Lars , Møgelvang Jens , Henriksen Ole , Henriksen Jens H.
Published: March 2007

Whether the central blood volume is reduced or expanded in cirrhosis is still under debate. Accordingly, the current study was undertaken to assess the volume of the heart cavities. Ten cirrhotic patients and matched controls had their right and left ventricular end-diastolic volumes (RVDV and LVDV), and end-systolic volumes (RVSV and LVSV) determined by magnetic resonance imaging (MRI). RVDV (122 vs. control 166 mL, P < .02), RVSV (41 vs. 80 mL, P < .02) and right atrial volume (47 vs. 64 mL, P < .05) were significantly reduced in the patients. In contrast, LVDV (134 vs. 129 mL, NS), LVSV (54 vs. 40 mL, NS), and left atrial volume (70 vs. 57 mL, P = .08) were normal or slightly increased. The right ejection fraction (68% vs. 53%, P < .05) was significantly increased, but the left ejection fraction was slightly reduced (61% vs. 69%, NS). The central and arterial blood volume (CBV), assessed as the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P < .05). The noncentral blood volume (4.43 vs. 3.64 L, P < .02), plasma volume (4.05 vs. 3.27 L, P < .02), and CO (7.11 vs. control 5.22 L/ min, P < .01) were significantly increased in the patients. CCT (13.1 vs. 20.0 sec, P < .005) and the right ventricular transit time (0.79 vs. 1.35 sec, P < .005) were significantly reduced, but the left ventricular transit time was normal (0.91 vs. 0.88 sec, NS). Systemic vascular resistance was reduced (991 vs. 1,490 dyn ± sec/cm6, P < .01). Our results are in keeping with a hyperkinetic circulation in cirrhotic patients with central vascular underfilling with reduced right heart blood volume and central and arterial blood volume. The normal or slightly increased left heart blood volume suggests a complex pattern with a relatively decreased left ventricular function. The results support the concept of an abnormal distribution of the blood volume, with central and arterial underfilling (consequent on the combination of decreased systemic vascular resistance and left ventricular dysfunction) as major elements in the abnormal fluid homeostasis in cirrhosis. (Hepatology 1995;22:472-478.)
Synaptosomal glutamate transport in thioacetamide-induced hepatic encephalopathy in the rat
Authors: Oppong Kofi N. W. , Bartlett Kim , Record Christopher O. , Al Mardini Hanan
Published: March 2007

Dysfunction of excitatory glutamatergic neurotransmission has been implicated in the cause of hepatic encephalopathy. Brain microdialysis studies in various animal models of portal systemic encephalopathy (PSE) and encephalopathy associated with acute liver failure, have established that an increase in extracellular glutamate occurs but the mechanisms of this are unclear. We have measured oxygen consumption, citrate synthase activity (as indices of energy state and mitochondrial content, respectively), calcium-dependent glutamate release, and high-affinity, sodium-dependent glutamate uptake by synaptosomes prepared from rats with thioacetamide-induced encephalopathy. (2 doses of thioacetamide 200 mg/kg with a 24-hour interval). Synaptosomes were prepared either by a modified P2 method (glutamate release study) or by discontinuous sucrose density gradient centrifugation (all other studies). There was no significant difference in synaptosomal oxygen consumption, citrate synthase activity, glutamate release, total synaptosomal glutamate content, or the Kd for glutamate uptake between the encephalopathy group and the controls. However, there was a marked decrease in the maximal velocity of transport (Vmax) for glutamate uptake in synaptosomes from encephalopathic rats, 2.64 versus 4.40 nmol/min/mg (P < .05). The results of this study provide evidence of impaired glutamate uptake in the rat thioacetamide model of hepatic encephalopathy, which could account for the elevated extracellular glutamate seen in the condition. (Hepatology 1995; 22:553-558.)
Downregulation of male-specific cytochrome P450s 2C11 and 3A2 in bile duct-ligated male rats: Importance to reduced hepatic content of cytochrome P450 in cholestasis
Authors: Chen Jiezhong , Murray Michael , Liddle Christopher , Jiang Xing-Mai , Farrell Geoffrey C.
Published: March 2007

The effects of bile duct ligation (BDL) on the activity and content of individual hepatic mixed-function oxidases (MFOs) was examined. Five days after BDL, hepatic microsomal total cytochrome P450 (CYP) content and NADPH-cytochrome P450-reductase (P450-reductase) activity were reduced to 56% and 57% of control, respectively. MFO activities attributable to the sexually undifferentiated CYPs 1A, 2A1, 2C6, and 2E1 were decreased to 32% to 52% of control, but the activities of two male sex-specific CYPs, 2C11 and 3A2, were reduced to a significantly greater extent (P < .05). The misrosomal contents of CYP proteins 2C6 and 2E1 were decreased after BDL to 61% and 63% of control, whereas 2C11 and 3A2 proteins were 21% and 45% of control. Corresponding reductions of the messenger RNA (mRNA) species for CYP 2C11 (9% of control) and 3A2 (37%) were detected, whereas there was no reduction of 2C6 mRNA. These findings are consistent with downregulation of the CYP 2C11 and 3A2 genes. Nuclear run-on studies performed 3 days after BDL showed that there was a generalized impairment of gene transcription after BDL, but a disproportionate reduction in transcription of CYPs 2C11 and 3A2. A possible explanation for downregulation of CYP 2C11 and 3A2 was provided by the observation that serum estradiol concentrations were threefold greater in BDL male rats, while serum testosterone was reduced; estradiol is known to downregulate CYPs 2C11 and 3A2. It is concluded that male sex-specific CYP enzymes are decreased to a greater extent than other microsomal proteins in BDL male rats. It is proposed that the reduced activity of steroid metabolizing enzymes, which occurs after BDL, results in altered serum sex steroid concentrations, which, in turn, lead to decreased transcription of CYP 2C11 and 3A2 genes. (Hepatology 1995; 580-587.)
Reduced antioxidative capacity in liver mitochondria from bile duct ligated rats
Authors: Krähenbühl Stephan , Talos Christine , Lauterburg Bernhard H. , Reichen Jürg
Published: March 2007

Lipid peroxidation and antioxidative mechanisms were investigated in liver mitochondria from bile duct ligated rats (BDL rats) and correlated with the activity of enzyme complexes of the electron transport chain. In comparison to pair-fed control rats, BDL rats had increased concentrations of thiobarbituric acid reacting substances (TBARS) per gram of liver and per milligram of mitochondrial protein 3, 7, 14, and 28 days after surgery. The hepatic glutathione (GSH) content was decreased in BDL rats 28 days after surgery when expressed per gram of liver but equal between BDL and control rats when expressed per liver. The mitochondrial GSH content was decreased in BDL rats by 20% to 33% from day 7 after surgery. The concentrations of ubiquinone-9 and ubiquinone-10, substances involved in electron transport and efficient antioxidants, were both decreased in BDL rats 14 and 28 days after surgery per gram of liver and per milligram of mitochondrial protein. When expressed per liver, ubiquinone-9 was decreased in BDL rats from day 7 after surgery. In comparison with controls, the decrease in total mitochondrial ubiquinone content in BDL rats averaged 52% 14 days and 38% 28 days after surgery. The activity of the succinate:ferricytochrome c oxidoreductase (complexes II and III of the electron transport chain) was decreased in BDL rats at days 7, 14, and 28 after surgery, and the activity of the ferrocytochrome c:oxygen oxidoreductase (complex IV) was reduced at 14 and 28 days after surgery. The mitochondrial concentration of TBARS showed a negative and the concentrations of GSH and ubiquinone a positive correlation with the activity of the succinate:ferricytochrome c oxidoreductase. We conclude that the mitochondrial concentration of antioxidants such as GSH and ubiquinone decreases in BDL rats, whereas the concentration of lipid peroxidation products increases. Hepatic mitochondrial dysfunction in BDL rats may at least partially result from oxidative damage to mitochondrial lipids and/or proteins. (Hepatology 1995;22:607-612.)
Differential activation of transcription factors NF-κB and AP-1 in rat liver macrophages
Authors: Tran-Thi Thuy-Anh , Decker Karl , Baeuerle Patrick A.
Published: March 2007

Liver macrophages (Kupffer cells) respond to many stimulations with the production of bioactive substances including cytokines, eicosanoids, and inorganic radicals. In this study the activation of transcription factors by substances inducing cytokine gene expression or superoxide formation in rat Kupffer cells was examined. Using primary cultures of rat Kupffer cells the role of NF-κB and activator protein 1 (AP-1) in the expression of the tumor necrosis factor-alpha (TNF-α) gene by lipopolysaccharide (LPS) was investigated. Both transcription factors were strongly activated but with different kinetics. Maximal DNA-binding activity was induced with 50 ng of LPS/mL of medium and persisted for at least 24 hours. At that time, NF-κB- as well as AP-1-DNA complexes decreased their mobilities in native gels. Among the cytokines tested only TNF-α and macrophage colony-stimulating factor (M-CSF) were able to activate NF-κB in Kupffer cells. Phorbol ester and zymosan activated AP-1 but not NF-κB; the treatment of zymosan yielding a modified form of AP-1. Of all substances found to interfere with TNF-α production by Kupffer cells (pyrrolidine dithiocarbamate, dexamethasone, prostaglandin E2, interleukin [IL]-4, IL-10, and transforming growth factor-beta [TGF-β]) only pyrrolidine dithiocarbamate was able to completely inhibit the activation of NF-κB by LPS. Although not abrogating the LPS activation of NF-κB, dexamethasone inhibited that of AP-1. The results indicate a direct participation of NF-κkB in the regulation of TNF-α synthesis and a differential effect of LPS on NF-κB and AP-1, respectively. (Hepatology 1995; 22:613-619.)
Rat hepatocytes attach to laminin present in liver biomatrix proteins by an Mg++-dependent mechanism
Authors: De Lourdes Ponce Maria , Rojkind Marcos
Published: March 2007

Laminin belongs to a family of proteins that contains at least seven variants. Together with fibronectin, it is the most important cell-adhesion protein. Recent data from various laboratories have suggested that liver sinusoidal laminins differ from Engelbert-Holmes-Swarm tumor laminin (laminin 1), because the former contain α2 instead of α1 chains. Therefore, we compared the adhesion of hepatocytes to laminin 1 and a matrix extracted with dilute acetic acid from liver biomatrix (LBP). We show that LBP contains laminin and that this extracellular matrix protein is the main adhesion protern. Close to 70% of the hepatocytes attach to LBP after 15 minutes of incubation at 37°C. Cell adhesion was Mg++ and Mn++-dependent and Ca++- and insulin-independent. Ethylenediaminetetraacetic acid prevented cell adhesion in the presence of divalent cations. We show that synthetic cell-adhesion peptide sequences present in laminin 1 (RGD and YIGSR) or an antibody to the cellbinding domain (SIKVAV) of the α chain do not prevent hepatocyte adhesion to LBP. We also show that LBP has cell specificity; hepatocytes adhere to it preferentially when compared with other epithelial and mesenchymal cell lines. We suggest that because of the differences in chain composition of laminin 1 and liver sinusoidal laminins as well as the described differences in cell adhesion to the two substrata, further studies are needed to determine the actual composition of liver laminin and establish the chains and domains to which hepatocytes adhere. (Hepatology 1995;22:620-628.)