bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondrial Dysfunction During Anoxia/Reoxygenation Injury of Liver Sinusoidal Endothelial Cells
Authors: Fujii Yuichi , Johnson Michael E. , Gores Gregory J.
Published: March 2007

ABSTRACT

Sinusoidal endothelial cell injury plays a pivotal role in anoxia/reoxygenation liver damage. However, the mechanisms culminating in anoxia/reoxygenation endothelial cell injury remain unclear. Our aims were to determine whether anoxia/reoxygenation injury of sinusoidal endothelial cells causes mitochondrial dysfunction. In cultured rat liver sinusoidal endothelial cells, the mitochondrial membrane potential, cytosolic free calcium and cytosolic pH were quantitated by means of fluorescent probes and multiparameter digitized video microscopy. Cell viability was measured on the basis of lactate dehydrogenase release, and ATP was quantitated with a luciferin/luciferase assay. Mitochondrial membrane potential was stable during 90 min of aerobic perfusion. After 60 and 90 min of anoxia, mitochondrial membrane potential decreased gradually to 97% ± 6% and 79% ± 7% of the basal value, respectively. However, mitochondrial membrane potential decreased abruptly with reoxygenation after 60 min of anoxia to 45% ± 12% of the basal value and did not recover over 30 min of aerobic perifusion. Loss of mitochondrial membrane potential could not be attributed to changes of cytosolic free calcium, cytosolic pH, nitric oxide generation or activity of poly(ADP–ribose) polymerase. The antioxidants TEMPO (2,2,6,6–tetramethylpiperidine–N–oxyl) and Trolox (6–hydroxy–2,5,7,8–tetramethyl–chroman–2–carboxylic acid) protected against both loss of mitochondrial membrane potential and cell viability. In contrast, reduced glutathione depletion by diethyl maleate or phorone potentiated mitochondrial depolarization and cell killing. Cyclosporine plus trifluoperazine also protected against loss of mitochondrial membrane potential and cell killing, suggesting that the mitochondrial membrane permeability transition was responsible for these events. Cytoprotection correlated better with preservation of the mitochondrial membrane potential than with cellular ATP levels. These data demonstrate that mitochondrial dysfunction is a critical event in anoxia/reoxygenation injury of liver sinusoidal endothelial cells, which can be therapeutically targeted. (Hepatology 1994;20:177-185.)
Urokinase and Type I Plasminogen Activator Inhibitor Production by Normal Human Hepatocytes: Modulation by Inflammatory Agents
Authors: Busso Nathalie , Nicodeme Edwige , Chesne Christophe , Guillouzo André , Belin Dominique , Hyafil François
Published: March 2007

ABSTRACT

We examined the effects of inflammatory cytokines (interleukin–1β, tumor necrosis factor–α and transforming growth factor–β) on the plasminogen activator system (urokinase, tissue–type plasminogen activator, type 1 plasminogen activator inhibitor) in primary cultures of human hepatocytes. We show that interleuklin–1β and tumor necrosis factor–α increase urokinase–type plasminogen activator production, reinforcing the concept that increased urokinase production is associated with inflammatory processes. By contrast, the same agents (i.e., interleukin–1β and tumor necrosis factor–α) do not stimulate plasminogen activator inhibitor type 1 production. This latter observation rules out hepatocytes as a major cellular source of plasmatic plasminogen activator inhibitor type 1 during acute–phase-related responses. Among the inflammatory agents used, transforming growth factor–β was found to be the most effective modulator of both urokinase–type plasminogen activator and plasminogen activator inhibitor type 1, inducing severalfold increases of activity of urokinase–type plasminogen activator, antigen and the corresponding mRNA and increasing plasminogen activator inhibitor type 1 antigen and mRNA levels. Urokinase–type plasminogen activator and plasminogen activator inhibitor type 1 modulation by transforming growth factor–β may play a critical role in hepatic pathophysiology. (Hepatology 1994;20:186-190.)
Heterogeneity in Hepatic Transport of Somatostatin Analog Octapeptides
Authors: Fricker Gert , Dubost Valerie , Schwab Dietmar , Bruns Christian , Thiele Christoph
Published: March 2007

ABSTRACT

Hepatic transport of the synthetic somatostatin analog octreotide—SMS 201-995, (d)Phe-Cys-Phe-(d)Trp-Lys-Thr-Cys–Throl—and its novel derivative

N

–α–(α–D–glucosyl(1-4)–1–deoxy–D–fructosyl)–octreotide—SDZ CO–611,

N

–α–(α–D–glucosyl(1-4)–1–deoxy–D–fructosyl)–(d)Phe-Cys-Phe-(d)Trp-Lys-Thr-Cys–Throl—was studied. In rats SMS 201-995 showed a plasma elimination half–life of 1.2 ± 0.2 hr; that of SDZ CO–611 was 1.9 ± 0.3 hours. Within 120 min 66% of a mesenterically injected 4.4–nmol dose of SMS 201-995 was excreted in bile, but only 5.3% of SDZ CO–611 was excreted in bile. Biliary concentration of SMS 201-995 showed a maximum enrichment of 540–fold ± 75–fold over peripheral blood concentration, indicating hepatic transport mechanisms different from simple diffusion. Comparison of plasma profiles of both peptides after mesenteric and femoral administration demonstrated the relative importance of hepatic extraction for SMS 201-995 but not for SDZ CO–611. The mode of extraction was studied by means of multiple–indicator dilution in isolated perfused rat liver, with inulin as nonpermeable marker. Ratio plots, ln([inulin]/[peptide]) vs. time, exhibited decreasing slopes for SMS 201-995, suggesting very rapid binding to hepatocyte membranes. The slope of the ratio plot of (inulin/SDZ CO–611) was almost zero even at low doses (down to 0.2 μg), implying mainly extracellular distribution and nonhepatic elimination. Binding assays indicated the absence of somatostatin receptors in sinusoidal hepatocyte membranes. However, SMS 201-995 and SDZ CO–611 bound with high affinity to somatostatin receptors in rat cortical membranes. Multiple–indicator dilution experiments in presence of increasing cholyltaurine concentrations suggested an interaction of SMS 201-995 with sinusoidal bile salt transport. In isolated hepatocytes, uptake of SMS 201-995 was saturable and showed mutual inhibition with cholyltaurine. The results indicate that SMS 201-995 transport is different from receptor mediated endocytosis as known for peptide hormones and elimination pathways of SDZ CO–611 other than biliary excretion. (Hepatology 1994;20:191-200.)
Effect of Obstructive Cholestasis on Membrane Traffic and Domain–Specific Expression of Plasma Membrane Proteins in Rat Liver Parenchmal Cells
Authors: Stieger Bruno , Meier Peter J. , Landmann Lukas
Published: March 2007

ABSTRACT

We investigated the effect of bile duct ligation and its release on membrane traffic and plasma membrane protein distribution in rat hepatocytes. Immunofluorescence studies with monoclonal antibodies against six domain–specific surface antigens revealed that bile duct ligation leads to an accumulation of pericanalicular vesicles containing canalicular antigens. All apical antigens could be demonstrated in the basolateral plasma membrane, whereas only one out of three basolateral antigens redistributed to the canalicular plasma membrane. After release of bile duct ligation, the accumulated pericanalicular vesicles disappeared within minutes, whereas the plasma membrane polarity was not restored within 1 hr. Monitoring secretion of polymeric IgA and horseradish peroxidase into bile demonstrated that bile duct ligation also inhibits the transcytotic vesicle pathway and severely impairs the function of tight junctions. In contrast, bile duct ligation appears not to affect the endoplasmic reticulum to basolateral membrane traffic as assessed by determination of newly synthesized albumin and transferrin in serum nor does it influence receptor mediated endocytosis at the basolateral plasma membrane. (Hepatology 1994;20:201-212.)
The Effect of Increased Hepatic Sitosterol on the Regulation of 3–Hydroxy–3–Methylglutaryl—Coenzyme A Reductase and Cholesterol 7α–Hydroxylase in the Rat and Sitosterolemic Homozygotes
Authors: Shefer Sarah , Salen Gerald , Bullock John , Nguyen Lien B. , Ness Gene C. , Vhao Zhihong , Belamarich Peter F. , Chowdhary Indu , Lerner Susan , Batta Ashok K. , Tint Stephen G.
Published: March 2007

ABSTRACT

We investigated hepatic cholesterol homeostasis in four homozygous sitosterolemic subjects from two unrelated families who showed enhanced absorption, diminished removal and increased tissue and plasma concentrations of sitosterol (24–ethyl cholesterol). Measurements of hepatic 3–hydroxy–3–methylglutaryl coenzyme A reductase activities were correlated with steady state messenger RNA levels and related to cholesterol 7α–hydroxylase activities in the sitosterolemic homozygotes and nine controls. Similar determinations were made in rats infused intravenously with sitosterol so that hepatic and plasma sitosterol concentrations increased to about 10% of total sterols to resemble the human disease sitosterolemia. In the four sitosterolemic homozygotes, hepatic 3–hydroxy–3–methylglutaryl coenzyme A reductase activities were markedly reduced (12% of normal), and steady state 3–hydroxy–3–methylglutaryl coenzyme A reductase messenger RNA levels barely detected. In contrast, hepatic 3–hydroxy–3–methylglutaryl coenzyme A reductase activities and messenger RNA levels were not decreased in rats with similarly elevated hepatic sitosterol concentrations. However, hepatic cholesterol 7α–hydroxylase activity was inhibited 30% in both the sitosterolemic homozygotes and rats with high liver sitosterol concentrations. Plasma cholesterol concentrations increased 120% in the sitosterol–infused rats and 29% in the untreated human homozygotes. These results demonstrate that high–tissue sitosterol concentrations do not inhibit hepatic 3–hydroxy–3–methylglutaryl coenzyme A reductase activity or steady state messenger RNA levels and that they competitively block cholesterol 7α–hydroxylase activity and raise plasma cholesterol levels. Thus the deficiency of 3–hydroxy–3–methylglutaryl coenzyme A reductase in the liver of sitosterolemic homozygotes is inherited and not due to the hepatic accumulation of sitosterol. In distinction, elevated hepatic sitosterol concentrations increase plasma cholesterol levels by competitively suppressing cholesterol 7α–hydroxylase activity. (Hepatology 1994;20:213–219.).
Hepatic Biliary Transport After Hepatocyte Transplantation in Eizai Hyperbilirubinemic Rats
Authors: Hamaguchi Hiromitsu , Yamaguchi Yasuo , Goto Mataro , Misumi Mikio , Hisama Naoya , Miyanari Nobutomo , Mori Katsutaka , Ogawa Michio
Published: March 2007

ABSTRACT

The Eizai hyperbilirubinemic rat (EHBR) is a Sprague–Dawley mutant rat with conjugated hyperbilirubinemia. Eizai hyperbilirubinemic rats have impaired canalicular excretory transport of organic anions, bile acid glucuronide and sulfate. Eizai hyperbilirubinemic rats, with and without a 68% partial hepatectomy, were treated by an intraportal injection of 1×107 wild–type Sprague–Dawley mutant rat hepatocytes. Serum bilirubin concentrations decreased significantly after hepatectomy and intraportal injection. Biliary excretion was demonstrated by biliary transport of indocyanine and sulfobromophthalein into the bile. These results indicate that hepatic transport of bile acid conjugates in Eizai hyperbilirubinemic rats can be restored by hepatocyte transplantation in conjunction with the recipient's excretory biliary system. (Hepatology 1994;20:220–224.)
Tetrahydroaminoacridine–Induced Ribosomal Changes and Inhibition of Protein Synthesis in Rat Hepatocyte Suspensions
Authors: Fariss Marc W. , Johnsen Sharon A. , Walton Lloyd P. , Mumaw Virgil R. , Ray Sidhartha D.
Published: March 2007

ABSTRACT

Tacrine (tetrahydroaminoacridine) is currently the only drug approved for the treatment of Alzheimer's disease. Unfortunately, tetrahydroaminoacridine therapy is often limited by this drug's propensity to induce reversible hepatotoxicity. Using suspensions of freshly isolated rat hepatocytes, we investigated the mechanism of tetrahydroaminoacridine cytotoxicity by examining the effect of tetrahydroaminoacridine on hepatocyte viability, protein synthesis, protein, DNA and RNA levels and ultrastructure. Our experimental findings support the explanation that tetrahydroaminoacridine–induced hepatotoxicity results from tetrahydroaminoacridine's adverse effect on protein synthesis and ribosomal structure and function. We found that viable, tetrahydroaminoacridine–treated hepatocytes (1.0 to 2.0 mmol/L or 118 to 235 μg/106 cells) demonstrated a dose–dependent and dramatic aggregation of ribosomes on endoplasmic reticulum as well as the aggregation of other nucleic acids found in the nucleus (chromatin) and in mitochondria. These electron microscopy data suggest that tetrahydroaminoacridine treatment results in severe ribosomal dysfunction. This was confirmed by the observed rapid loss of cellular RNA content (but not DNA or protein) and the rapid and complete inhibition of protein synthesis in tetrahydroaminoacridine–treated cells (lowest concentration tested was 0.5 mmol/L or 58 μg/106 cells). Thus tetrahydroaminoacridine treatment appears to aggregate hepatocellular nucleic acids, and in doing so adversely affects ribosomal function and protein synthesis. We propose that these adverse effects of exposure to tetrahydroaminoacridine are responsible for tetrahydroaminoacridine–induced hepatotoxicity. (Hepatology 1994;20:•••.)
Current Therapeutic Relevance of Liver Gene Transfer
Authors: Heard Jean Michel
Published: March 2007

ABSTRACT

The liver represents a model organ for gene therapy. A method has been developed for hepatic gene transfer in vivo by the direct infusion of recombinant retroviral vectors into the portal vasculature, which results in the persistent expression of exogenous genes. To determine if these technologies are applicable for the treatment of hemophilia B patients, preclinical efficacy studies were done in a hemophilia B dog model. When the canine factor IX complementary DNA was transduced directly into the hepatocytes of affected dogs in vivo, the animals constitutively expressed low levels of canine factor IX for more than 5 months. Persistent expression of the clotting factor resulted in reductions of whole blood clotting and partial thromboplastin times of the treated animals. Thus, long–term treatment of hemophilia B patients may be feasible by direct hepatic gene therapy in vivo.
Is Hepatitis B Infection An Indication for Orthotopic Liver Transplantation? the Answer, My Friend, Is Blowin' in the Wind
Authors: Villamil Federico G.
Published: March 2007

ABSTRACT

Background.

The role of liver transplantation in patients positive for the hepatitis B surface antigen (HBsAg) is controversial because of the high rate of recurrent hepatitis B virus (HBV) infection. It has not been determined whether this risk is greater for certain patients and whether the administration of anti–hepatitis B surface antigen (anti–HBe) immune globulin is beneficial.

Methods.

We conducted a retrospective study at 17 European centers of 372 consecutive HBsAg–positive patients who underwent liver transplantation between 1977 and 1990. Recurrence of HBV infection was defined as the reappearance of HBsAg in serum.

Results.

For all 334 patients with follow–up data, the mean (± SE) three–year actuarial risk of recurrence of HBV was 50 ± 3 percent. The risk was 87 ± 4 percent among 163 patients with HBV–related cirrhosis. 32 ± 5 percent among 110 patients with cirrhosis related to hepatitis delta virus, 40 ± 16 percent among 14 patients with fulminant hepatitis delta infection, and 17 ± 7 percent among 39 patients with fulminant HBV infection (P<0.001). Among the patients with HBV–related cirrhosis, the risk of HBV recurrence was greatest (83 ± 8 percent) in those who were seropositive for HBV DNA at the time of transplantation and lowest (56 ± 7 percent) in those with neither HBV DNA nor hepatitis B e antigen detectable in serum. With respect to the use of passive prophylaxis with anti–HBs immune globulin, the risk of HBV recurrence was 75 ± 5 percent among the 67 patients given no immunoprophylaxis, 74 ± 5 percent among the 83 treated for two months, and 36 ± 4 percent among the 209 treated for six months or longer (P<0.001). In a multivariate analysis the predictors of a lower risk of HBV recurrence were the long–term administration of the immune globulin, hepatitis delta virus superinfection, and acute liver disease. For the entire study cohort, survival was 75 percent at one year and 63 percent at three years, but for those in whom HBV infection recurred, survival was 68 percent at one year and 44 percent at three years.

Conclusions.

In this retrospective study of HBsAg–positive patients, liver transplantation had better results in those who had fulminant hepatitis or delta virus superinfection. An absence of viral replication at the time of transplantation and long–term immunoprophylaxis were associated with a reduced risk of recurrent HBV infection and reduced mortality.
Detection and Distribution of Hepatitis C—Specific Antigens in Naturally Infected Liver
Authors: Blight Keril , Lesniewski Richard R. , Labrooy Justin T. , Gowans Eric J.
Published: March 2007

Hepatitis C virus antigen expression was examined using peptide antibodies in liver tissue taken at biopsy from four chronic carriers of hepatitis C virus. Hepatitis C virus antigens E2/NS1, NS3, NS4 and NS5 were widespread in unfixed frozen liver sections and were present as distinct granules or foci within the cytoplasm of hepatocytes and in infiltrating lymphocytes in portal tracts. Fixation of frozen sections with 1% formalin improved the histological appearance of the tissue section without reducing the sensitivity of antigen detection. However, in tissue sections fixed in acetone, chloroform, carbon tetrachloride or methyl carnoys, detection of all hepatocyte–specific hepatitis C virus antigens was significantly reduced. Dual immunostaining of liver sections for lymphocyte cluster of differentiation markers and hepatitis C virus antigens determined that a high proportion of cluster of differentiation 20—positive B cells and cluster of differentiation 4—and cluster of differentiation 8—positive T cells, predominant in lymphoid aggregates, were positive for hepatitis C virus antigens. (Hepatology 1994;20:553-557).
A Multicenter Randomized Controlled Dose Study of Ursodeoxycholic Acid for Chronic Hepatitis C
Authors: Takano Susumu , Ito Yoshimi , Yokosuka Osamu , Ohto Masao , Uchiumi Katsuo , Hirota Katsutaro , Omata Masao
Published: March 2007

The effect of ursodeoxycholic acid on liver function tests and on bile acid metabolism was investigated in a multi–center randomized controlled dose study for chronic hepatitis C. Twenty, 18 and 19 patients were administered 150, 600 and 900 mg/day, respectively of ursodeoxycholic acid every day for 16 wk. Serum liver parameters and bile acid composition in the treatment groups were compared with 17 control patients. A similarly significant decrease of serum alanine aminotransferase and serum γ–glutamyltransferase was observed in patients administered 600 and 900 mg of ursodeoxycholic acid. Serum bile acid composition was determined by high–performance liquid chromatography. At entry, the relative proportions of major bile acids were similar to those observed in normal individuals. Maximal concentrations of total ursodeoxycholic acid were

0.30 μmol/L, 5.59 μmol/L, 21.42 μmol/L and 14.73 μmol/L

in the control, 150, 600 and 900 mg/day groups, respectively. The fraction of the total ursodeoxycholic acid increased in a dose–dependent manner, and it was significantly higher than in controls (p < 0.001). The hydrophobicity index of bile acids was calculated by the method of Heuman, and its correlation with serum parameter levels was analyzed. In the 600 and 900 mg/day dose groups, serum alanine aminotransferase decreased in the cases in which hydrophobicity index significantly decreased during treatment. The same correlation was observed between the hydrophobicity index and serum γ = glutamyltransferase in these two groups. There was no correlation between these parameters in the control and 150–mg groups. There was no correlation between reduction rate of serum alanine aminotransferase and initial liver histology. These data suggest that ursodeoxycholic acid at a dose of 600 mg/day may be effective in improving liver function in patients with chronic hepatitis C. (Hepatology 1994;20:558-564).
Predictive Factors of Early Postoperative Graft Function in Human Liver Transplantation
Authors: González Xavier F. , Rimola Antoni , Grande Luis , Antolin Maria , Garcia-Valdecasas Juan C. , Fuster Jose , Lacy Antonio M. , Cugat Esteban , Visa Jose , Rodés Joan
Published: March 2007

To identify factors predictive of early postoperative graft function, we analyzed 54 variables—including easily available clinical and laboratory data prospectively obtained from organ donors, transplant recipients and surgical procedures in 168 consecutive liver transplantations. Early postoperative graft function was classified into three groups according to a scoring system ranging from 3 to 9 based on peak serum ALT values, mean bile output and lowest prothrombin activity measured during the 72 hr after transplant: group 1 (score 3 to 4, good graft function; n = 73), group 2 (score 5 to 6, moderate dysfunction; n = 50) and group 3 (score, 7 to 9, severe dysfunction; n = 45). In univariate analyses, 8 of the 54 variables analyzed were statistically significant (p < 0.05) predictors of severe graft dysfunction: high serum sodium concentration and brain death caused by cranial trauma in organ donors, advanced age and low prothrombin activity in transplant recipients, prolonged total ischemia time and large transfusions of red blood cells, fresh frozen plasma and platelets during surgery. After introduction of these eight variables in a multivariate analysis, only four were found to independently predict early postoperative graft function: donor serum sodium concentration, total ischemia time, platelet transfusion during surgery and recipient prothrombin activity. In 52 liver transplantations, in which the predictive value of liver tissue adenine nucleotide concentration and several biochemical sensitive markers of donor nutritional status was also analyzed, only the ATP level in liver tissue obtained at the time of organ reperfusion was identified as an independent predictor of initial graft function. We conclude that the degree of early postoperative graft dysfunction in liver transplantation can be predicted on the basis of data from organ donors, transplant recipients and surgical events. (Hepatology 1994;20:565-573).
Impact of Shunt Surgery for Variceal Bleeding in the Natural History of Ascites in Cirrhosis: A Retrospective Study
Authors: Castells Antoni , Saló Joan , Planas Ramon , Quer Juan Carlos , Ginès Angels , Boix Jaume , Ginès Pere , Gassull Miquel Angel , Terés Josep , Arroyo Vicente , Rodés Joan
Published: March 2007

Despite the efficacy of shunt surgery in the treatment of variceal bleeding, less effective nonoperative therapies are being substituted because surgical shunt does not modify survival and increases hepatic encephalopathy. However, the real impact of shunt surgery on the natural history of ascites and its complications has not been established. The course of 204 Child–Pugh A and B cirrhotic patients with variceal bleeding included in three controlled trials of our units who survived first hospitalization was updated. Ninetyeight patients (group I) were treated by portacaval (56 patients) or distal splenorenal (42 patients) shunt, whereas 106 (group II) were treated by nonshunt procedures (sclerotherapy in 89 patients and staple transection in 17 patients). As expected, the 5–yr probability of variceal rebleeding was lower (13% vs. 44%) and hepatic encephalopathy higher (50% vs. 28%) in group I than in group II, and survival was similar (67% vs. 60%). Shunt surgery had a great impact on the natural history of ascites and its complications. The probability of occurrence of ascites (15% vs. 73%; p < 0.0001), spontaneous bacterial peritonitis (2% vs. 21%; p < 0.0001) and hepatorenal syndrome (4% vs. 21%; p < 0.01) was greatly reduced. These beneficial effects accounted for the lower percentage patients requiring readmissions (51% vs. 70%; p = 0.02) and shorter total time spent in hospital (14 + 22 vs. 26 + 39 days/patient p = 0.01) in group I. These data indicate that shunt surgery, in addition to reducing the probability of rebleeding, markedly decreases the probability of ascites, spontaneous bacterial peritonitis and hepatorenal syndrome development. Therefore, ascites and its complications should be considered in any therapeutic trial assessing the efficacy of surgical or percutaneous portacaval anastomosis on variceal bleeding. (Hepatology 1994;20:584–591).
Appearance of Sinusoidal Inclusion–Containing Endothelia Cells in Liver Disease
Authors: Iwamura Shinichi , Enzan Hideaki , Saibara Toshiji , Onishi Saburo , Yamamoto Yasutake
Published: March 2007

Sinusoidal “inclusion–containing endothelial cells” were studied histopathologically and immunohistochemically in various liver diseases, and their clinical importance was investigated. A total of 498 needle liver biopsies were examined. Endothelial inclusions inside the cells were recognized as eosinophilic granules in hematoxylin–eosin–stained sections. Electron microscopy showed that these inclusions corresponded to round cytoplasmic dense bodies with a single limiting membrane. The contents of these bodies were generally homogeneous, but sometimes heterogeneous. The inclusions appeared to contain protein, but were resistant to trypsin digestion, and immunohistochemistry failed to identify any immunoglobulins or hepatocyte–derived proteins. These endothelial cells also contained an increased number of micropinocytotic vesicles when compared with ordinary cells. The inclusion–containing endothelial cells appeared frequently in chronic hepatitis, but were relatively rare in other liver diseases. The incidence was higher in chronic aggressive hepatitis than in chronic persistent hepatitis or inactive cirrhosis. Although the density of these cells varied considerably even among patients with the same histological diagnosis and the phenotypical changes of these endothelial cells, assessed by monoclonal antibodies, were not apparent, the serum γ globulin level tended to increase in relation to the density of inclusion–containing endothelial cells and the correlation was significant in hepatitis C. (Hepatology 1994;20:604-610).
Hemodynamic Effects of α–Adrenergic Blockade With Prazosin in Cirrhotic Patients With Portal Hypertension
Authors: Albillos Agustin , Lledó Jose Luis , Bañares Rafael , Rossi Irma , Iborra Jerónimo , Calleja Jose Luis , Garrido Aurelio , Escartin Pedro , Bosch Jaime
Published: March 2007

This study was aimed at investigating whether the blockade of α1–adrenergic receptors could reduce portal pressure in cirrhosis. Splanchnic and systemic hemodynamics were measured in 12 cirrhotic patients with esophageal varices at baseline and 1 hr after oral administration of 2 mg of prazosin (acute study). Measurements were repeated in 10 of these 12 patients after a 3–mo course of 5 mg/12 hr of prazosin (long–term study). Short–term prazosin significantly lowered the hepatic venous pressure gradient from 20.1 ± 1.3 to 14.4 ± 0.9 mm Hg (—25.7%) (p < 0.01), and chronic prazosin reduced it to 16.5 ± 1.3 mm Hg (—19.1%) (p < 0.01). Hepatic blood flow was increased, thus changes in the hepatic venous pressure gradient resulted from a reduction in the estimated hepatic vascular resistance. Reductions in hepatic venous pressure gradient achieved after short–term and long–term prazosin were not significantly different. Reductions in mean arterial pressure and systemic vascular resistance were significantly greater after short–term than after long–term prazosin. Long–term prazosin was associated with significant increases in hepatic and intrinsic hepatic clearances of indocyanine green. This therapy also led to an increase in pulmonary capillary pressure (+ 28.6%, p < 0.05) and body weight (+3.06%, p < 0.01) and a decrease in hematocrit (—6.1%, p < 0.05) and urinary sodium excretion (—22.6%, p < 0.05). In contrast, there were no hemodynamic changes in a group of six cirrhotic patients receiving placebo. In cirrhotic patients, short–term prazosin lowers portal pressure by decreasing hepatic vascular resistance. These changes are maintained during long–term therapy, being associated with an improvement in liver function tests. Although attenuated, the arterial vasodilator effect of short–term prazosin persists during long–term therapy and seems to enhance fluid retention. (Hepatology 1994;20:611-617).
Parenteral Calcitonin for Metabolic Bone Disease Associated With Primary Biliary Cirrhosis
Authors: Crosignani Andrea , Battezzati Pier Maria , Albisetti Walter , Grandinetti Giuseppe , Pietrogrande Luca , Biffi Arianna , Zuin Massimo , Podda Mauro
Published: March 2007

No satisfactory treatment is available for metabolic bone disease associated with primary biliary cirrhosis. On the basis of the similarities to postmenopausal osteoporosis, the rationale exists for calcitonin to be tested in clinical studies in patients with primary biliary cirrhosis—associated osteoporosis. We evaluated the effect of calcitonin on bone metabolism and mineral density in 25 women with primary biliary cirrhosis and severe osteopenia. After 6 mo of observation, patients received a synthetic calcitonin or a control treatment consisting of less than one hundredth of the recommended dose of porcine calcitonin. The two treatments were administered in sequence to each patient for two 6–mo periods, with a 3–mo washout between them, according to a crossover design. After the observation period, oral calcium supplementation was started. Bone mineral density was measured by dual–photon absorptiometry of the lumbar spine at study entry and at the beginning and the end of each treatment period. During the observation period bone mineral density fell by 3.5% whereas during the following 6 mo it increased in both the patients who received calcitonin (4.3%) and those who received the control treatment (4.9%). Conversely, after the crossover, bone mineral density decreased during both calcitonin (–2.7%) and control treatment (–2.9%). A significant difference was observed between the two periods but not between the two treatments or between the two sequences of treatment administration. In conclusion, our findings indicate that parenterally administered calcitonin for 6 mo is ineffective in halting bone loss in patients with primary biliary cirrhosis—associated metabolic bone disease, whereas calcium supplementation may have a transient beneficial effect. (Hepatology 1994;20:633-637).
Changes of α1–Adrenergic Receptors in Human Liver During Intraabdominal Sepsis
Authors: Hwang Tsann-Long , Lau Ying-Tung , Huang Shu-Fang , Chen Miin-Fu , Liu Maw-Shung
Published: March 2007

We studied changes in α1–adrenergic receptors in human liver plasma membranes during intraabdominal sepsis using [3H]prazosin as a radioligand. Human liver tissues were obtained from nonseptic patients undergoing elective abdominal surgery (control group) and from patients with sepsis requiring laparotomy as a therapeutic measure (septic group). Septic patients were further divided into three subgroups on the basis of septic severity scores: mild sepsis (<21), moderate sepsis (22 to 32) and severe sepsis (>33). Plasma membranes were prepared by means of sucrose gradient centrifugation and were purified fivefold on the basis of the enrichment of the activity of the marker enzyme, 5′–nucleotidase. [3H]prazosin–binding studies show that the maximal binding capacity was increased by 49.6% (p <0.01) in mild sepsis, relatively unchanged in moderate sepsis and decreased by 33.4% (p < 0.05) in severe sepsis (in femtomoles per milligram: 193.7 ± 5.7 for control [n = 6], 289.8 ± 23.4 for mild sepsis [n = 4], 192.3 ± 16.3 for moderate sepsis (n = 4), 129.1 ± 18.3 for severe sepsis [n = 5]). We found a significant inverse correlation (r = 0.85, p < 0.01) between changes in the densities of α1–adrenergic receptors and septic severity scores. These data indicate that α1–adrenergic receptors in human liver plasma membranes undergo dynamic changes during the development of sepsis — that is, the receptor number increased in mild sepsis, returned to a normal level in moderate sepsis and finally decreased in severe sepsis. Because α1–adrenergic receptor densities in human liver plasma membranes can be increased or decreased during the progression of septic shock, successful therapeutic interventions that aim to ameliorate glucose dyshomeostasis by way of α1–adrenergic receptor mediation may depend on appropriate timing of when interventions are given. These findings thus may contribute to a better remedy for hepatic glucose dyshomeostasis during sepsis. (Hepatology 1994;20:638–642).
Phase Ii Study of Transarterial Embolization in European Patients With Hepatocellular Carcinoma: Need for Controlled Trials
Authors: Bruix Jordi , Castells Antoni , Montanyà Xavier , Calvet Xavier , Brü Concepció , Ayuso Carmen , Jover Lluís , García Laura , Vilana Ramon , Boix Loreto , Rodés Joan
Published: March 2007

Our uncontrolled phase II study was aimed at assessing the efficacy of transarterial embolization in patients with hepatocellular carcinoma and to determine the parameters associated with a favorable response to treatment, improved survival or both. Fifty consecutive patients (25 corresponding to Okuda's stage I and 25 to stage II) with hepatocellular carcinoma (41 being multinodular or massive) were included. Transarterial embolization induced a self–limited postembolization syndrome that was well tolerated. Nevertheless, three patients died shortly after the procedure because of tumor progression (two cases) or progressive liver failure. A favorable response (extensive necrosis with reduction of tumor area greater than 50%) was achieved in 81% of the cases, and this result was independently (p < 0.05) related to a preserved performance status and to a lower alphafetoprotein concentration. The survival of the patients at 1 and 2 yr was 65% and 38%, respectively, better than the expected survival according to a mathematical model obtained from a historical series of untreated cases (42% and 20%, respectively). Cox regression analysis disclosed that both a favorable therapeutic response and a preserved physical condition (reflected by performance status of 0 or 1) were independently associated with better survival (regression coefficient –2.248 and 0.869, respectively). These data indicate that transarterial embolization has a marked antitumoral effect in patients with inoperable hepatocellular carcinoma and that the therapeutic success is associated with improved survival. Nevertheless, because the potential benefit for survival observed in this uncontrolled study appears to be moderate, prospective controlled trials to ascertain the real usefulness of this therapeutic approach are mandatory. (Hepatology 1994;20:643–650).
The Nature of Complications Following Liver Biopsy in Transplant Patients With Roux–En–Y Choledochojejunostomy
Authors: Galati Joseph S. , Monsour Howard P. , Donovan Jeremiah P. , Zetterman Rowen K. , Schafer Daniel F. , Langnas Alan N. , Shaw Byers W. , Sorrell Michael F.
Published: March 2007

Liver biopsy is an important diagnostic tool in the management of patients following orthotopic liver transplant. We evaluated complications following percutaneous liver biopsy in a group of liver transplant patients who had Roux–en–Y choledochojejunostomies fashioned as part of their biliary reconstruction during liver transplantation. Complications were divided into two major groups: septic complications (including fever, symptomatic bacteremia, cholangitis, infected hematoma and hypotension related to sepsis) and bleeding (defined as hypotension requiring volume expansion greater than 500 cm3 or blood transfusion, hemothorax, intrahepatic or peritoneal hemorrhage and hemobilia occurring within 1 wk of liver biopsy). One hundred ninety–two biopsies were performed in 46 patients with choledochojejunostomies, and 118 biopsies were carried out in an age– and sex–matched control group of patients with choledochocholedochostomy biliary anastomosis. There were no septic complications in the choledochojejunostomy patients and one (0.32%) septic complication in the choledochocholedochostomy patients (NS). Eight bleeding complications occurred (2.6%) in eight patients (8.3%). Five (2.6%) occurred in five (10.8%) of the choledochojejunostomy patients, vs. three (2.5%) in three (6.5%) choledochocholedochostomy patients (NS). None of the bleeding complications required surgical intervention or was fatal. We conclude that liver biopsy in posttransplant patients with Roux–en–Y choledochojejunostomies is a safe procedure and that the incidences of complications were similar in our two groups. The negligible incidence of septic complications in the choledochojejunostomy patients does not appear to warrant the administration of prophylactic antibiotics, as has been previously suggested. (Hepatology 1994;20:651-653).
The Eosinophil As An Effector Cell of the Immune Response During Hepatic Allograft Rejection
Authors: De Groen Piet C. , Kephart Gail M. , Gleich Gerald J. , Ludwig Jurgen
Published: March 2007

Objective:

To evaluate the role of the eosinophil granulocyte during hepatic allograft rejection.

Design:

(a) A retrospective case–control study and (b) a prospective study of consecutive liver transplant recipients.

Patients:

In the retrospective study, eight patients with severe rejection in the first month after liver transplantation were compared with six patients without rejection. In the prospective study, 20 consecutive patients were studied for the presence of liver allograft rejection between March 1989 and October 1989.

Measurements:

Absolute eosinophil counts were determined whenever blood was drawn. Serum was analyzed for the presence of two eosinophil granule proteins, major basic protein and eosinophil–derived neurotoxin, on days 7, 14 and 21 after transplantation. Liver biopsy specimens were stained for the presence of major basic protein by means of immunofluorescence using a double–antibody staining technique. The degree of eosinophil infiltration and degranulation was graded using a panel of representative slides.

Results:

Blood eosinophilia was increased in patients with hepatic allograft rejection (p < 0.05). Serum major basic protein and eosinophil–derived neurotoxin concentrations were similar in patients with and without rejection. Many portal tracts of patients with rejection contained an abundance of eosinophils, and staining for major basic protein revealed the presence of intact eosinophils. In addition, extracellular major basic protein was seen, sometimes in the absence of intact eosinophils or an extensive infiltrate. In patients with severe allograft rejection, major basic protein staining was present in littoral cells lining the sinusoids.

Conclusions:

Patients with severe rejection in the first month after liver transplantation often have blood eosinophilia and marked infiltration of portal tracts with eosinophils or evidence of eosinophil degranulation. The presence of major basic protein likely is direct evidence of tissue destruction and may indicate active rejection (major basic protein in eosinophils and extracellular major basic protein, presence of portal infiltrate) or the immediate postinflammatory rejection state (extracellular major basic protein and major basic protein inside littoral cells, absence of portal infiltrate and eosinophils, bile ducts damaged or vanished). These findings underline the importance of the eosinophil as an intergral part of the rejection process. We conclude that the presence of eosinophils or their secretion products in the first month after liver transplantation is an indicator of ongoing or recent allograft rejection. (Hepatology 1994;20:654-662).
Role of the Hepatic Artery in the Metabolism of Phenacetin and Acetaminophen: An Intravital Microscopic and Multiple–Indicator Dilution Study in Perfused Rat Liver
Authors: Pang Sandy K. , Sherman Igor A. , Schwab Andreas J. , Geng Wanping , Barker Ford , Dlugosz John A. , Cuerrier Guy , Goresky Carl A.
Published: March 2007

We studied the pattern of intermixing of the hepatic arterial and portal venous flows in a perfused rat liver preparation under constant flow (12 ml/min) with intravital epifluorescent microscopy; changes in the steady state extraction ratio of carbon 14—labeled phenacetin and tritiated acetaminophen, probes metabolized primarily in perivenous and periportal regions of the rat liver, respectively; and the spaces accessed by noneliminated reference indicators introduced as a bolus into the hepatic artery and portal vein at different hepatic arterial/portal venous flow regimens of 0:12, 2:10 and 4:8. The sinusoidal velocities for the hepatic arterial— and portal venous (hepatic arterial/portal venous flow at 4:8)—infused fluorescein isothiocyanate—erythrocytes (100 μ1/min) were 327 ± 78 and 301 ± 63 μm/sec, respectively, and the velocity for the solely portal venous–perfused liver (12 ml/min) was 347 ± 74 μm/sec the flow–weighted sinusoidal velocity was highly correlated to the sinusoidal volume for the dually perfused rat liver. Small but significant decreases in the extraction ratio of [14C]phenacetin (from 0.989 to 0.984 and 0.980) and tritiated acetaminophen (from 0.631 to 0.607 to 0.563), delivered simultaneously into the hepatic artery and portal vein, were observed with an increment of hepatic arterial flow within the same liver preparation; oxygen consumption rate also fell slightly, in parallel fashion. When a multiple–indicator dilution dose containing chromium 51—labeled RBCs, iodine 125—labeled albumin and tritiated water or [14C]urea was injected into the hepatic artery (which accesses both the peribiliary capillary plexus [nonsinusoidal] and the sinusoidal bed) and portal vein (which enters only the sinusoids) at 10–min intervals within each steady state, the blood volume, total albumin space, albumin Disse space, total water and parenchymal cellular water spaces were unchanged after portal venous injection for all hepatic arterial/portal venous flow ratios, suggesting that the arterial flow is ineffective in perturbing average sinusoidal flow dynamics. However, slightly larger total water spaces were obtained with hepatic arterial injection. This excess water space was almost completely accounted for by the “nonsinusoidal” extravascular space associated with the peribiliary capillary plexus; it averaged 0.03 ml/gm and was independent of flow. The anomaly, a reduced flow–weighted sinusoidal velocity for the dually perfused liver, an unchanged diameter of the terminal hepatic venule (32 μm) among the hepatic arterial/portal venous flow ratios and the reduction in the extraction ratio of the drug probes and oxygen consumption rates suggest that some of the arterial flow must have entered the sinusoids somewhat downstream. (Hepatology 1994;20:672-683).
Adaptive Sex–Dependent Changes in the Zonation of Carbohydrate and Lipid Metabolism in Rat Liver Lobules After Partial Hepatectomy
Authors: Van Noorden Cornelis J.F. , Vogels Ilse M.C. , James Jan
Published: March 2007

To evaluate changes in metabolic heterogeneity in rat liver lobules after partial hepatectomy, we measured parameters of carbohydrate and lipid metabolism cytophotometrically in periportal and pericentral zones of livers of mature female and male rats. Glycogen content was shown to be always higher in pericentral zones than in periportal zones. After a rapid depletion of glycogen stores during the first 8 hr after partial hepatectomy, the levels were restored to normal after 24 hr, but a significant depletion was found again at 48 hr after operation. These fluctuations were similar in female and male rat livers. The lipid content in control rat livers was low and was mainly localized in periportal zones. Partial hepatectomy caused a significant increase in lipid content after 24 to 48 hr in periportal zones only, which was distinctly higher in female than in male rat livers. Activity of NADPH–producing glucose–6–phosphate dehydrogenase was heterogeneously distributed in lobules of female control rats with highest activity in pericentral zones, whereas a lower but evenly distributed activity was found in lobules of control male rats. The activity was not affected by partial hepatectomy in male rats, whereas the activity in female rat livers decreased to levels found in male rats at 24 to 48 hr after operation. Another NADPH–producing enzyme, malate dehydrogenase, showed the highest activity pericentrally in female rats, and a low activity was evenly distributed in male rats. The activity did not change significantly after partial hepatectomy. The ketogenic enzyme β–hydroxybutyrate dehydrogenase showed the highest activity in pericentral zones of control livers. The activity in male rat livers was almost twice as high as in female rat livers in both zones. Partial hepatectomy caused a distinct reduction in activity in both zones and both sexes, but the strongest reduction was found periportally. Alkaline phosphatase activity, which is linked with bile acid secretion by hepatocytes, was low in control male and female rats and was mainly found periportally. The activity was increased dramatically at 24 to 48 hr after partial hepatectomy in both zones and particularly in male rat livers. The index for the Krebs cycle, succinate dehydrogenase activity, was highest in periportal zones. At 24 to 48 hr after partial hepatectomy, this preferential zonation was lost, and the activity was slightly higher in pericentral zones. This reversal of zonation was found in all livers of female and male rats investigated. Because the metabolic changes after partial hepatectomy cannot be explained by hormonal changes that are known to occur after partial hepatectomy, we concluded that the metabolic zonation in rat liver lobules is dynamic, sex dependent and adaptive. (Hepatology 1994;20:714-724).
Posttranslational Events Involved in Griseofulvin–Induced Keratin Cytoskeleton Alterations
Authors: Salmhofer Hermann , Rainer Ingrid , Zatloukal Kurt , Denk Helmut
Published: March 2007

Alcoholic hepatitis is a disease associated with profound alterations of the hepatocytic intermediate filament cytoskeleton. Similar cytoskeletal alterations can be induced in mice with prolonged feeding of the fungistatic drug griseofulvin. Murine hepatocytic intermediate filaments are composed of equimolar amounts of keratin polypeptides A (type II) and D (type I). Griseofulvin intoxication of mice leads to diminution, derangement and even loss of the cytoplasmic keratin meshwork and formation of keratin–containing cytoplasmic inclusions, termed

Mallorybodies.

To study protein alterations leading to disturbance of keratin filament architecture, soluble keratin polypeptides and keratin filaments were purified from griseofulvin–damaged and control mouse livers. In griseofulvin–damaged livers, more acidic isoforms occurred in soluble keratin D, whereas the corresponding filaments had a polypeptide composition similar to that in controls.

In vivo

[32P]orthophosphate incorporation revealed that the shift of isoelectric forms toward more acidic spots was due to hyperphosphorylation of keratin D. The nature of the kinase(s) involved has yet to be elucidated. In addition, rapid proteolysis only of soluble keratin A was detected

in vitro

, and there is evidence for increased proteolysis in griseofulvin damage

in vivo

. The enzyme involved has features of a calpain–type protease. Posttranslational modifications play a substantial role in the disturbance of keratin intermediate filament homeostasis

in vivo

. (Hepatology 1994;20:731-740).