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1.
Case Rep Oncol ; 7(1): 92-6, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24575023

ABSTRACT

A 65-year-old man presented to our hospital with abdominal pain, dyspepsia and anorexia. Laboratory tests showed an altered liver function and abdomen ultrasonography revealed multiple liver nodules, suspected to be metastatic lesions. Serous tumor markers were elevated and a very high level of alpha-fetoprotein was found. Computer tomography confirmed the hepatic lesions and disclosed a thickening of the lesser curvature of the gastric wall. A subsequent endoscopy showed an ulcer on the lesser curvature. Biopsies taken from the gastric ulcer and the liver nodule revealed an adenocarcinoma, both of gastric origin. Shortly after the diagnosis, the patient's condition worsened and he died only 15 days later. This case report illustrates how alpha-fetoprotein-producing gastric adenocarcinomas have a high incidence of venous and lymphatic invasion and a rapid hepatic spread with a very poor prognosis.

3.
Gut ; 58(4): 582-4, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19299387

ABSTRACT

The use of polytetrafluoroethylene (PTFE)-covered prostheses improves trans-jugular intrahepatic porto-systemic shunt (TIPS) patency and decreases the incidence of clinical relapses and re-interventions. Therefore, the improvement provided by covered stents might expand the currently accepted recommendations for TIPS use. Stent-related occlusion of the hepatic vein with consequent ischaemia of the corresponding liver parenchyma emerges as a novel complication reported in at least 5% of patients implanted with coated stents. However, this complication was reported to be mild, without signs or symptoms of liver failure, and self-limiting. We report a case of segmental liver ischaemia following PTFE-covered stent placement resulting in a marked impairment in liver function in a patient with hepatitis C virus cirrhosis implanted because of refractory oesophageal bleeding, thus expanding the severity range of this new procedural complication. Moreover, we discuss the possible involvement of additional pathogenetic mechanisms other than out-flow obstruction in the onset of coated-stent induced congestive liver ischaemia.


Subject(s)
Drug-Eluting Stents/adverse effects , Ischemia/etiology , Liver Failure/etiology , Liver/blood supply , Portasystemic Shunt, Transjugular Intrahepatic/adverse effects , Humans , Ischemia/diagnosis , Liver Failure/diagnosis , Male , Middle Aged , Polytetrafluoroethylene , Portasystemic Shunt, Transjugular Intrahepatic/instrumentation , Tomography, X-Ray Computed , Ultrasonography, Doppler
4.
Gut ; 57(9): 1288-93, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18448567

ABSTRACT

BACKGROUND: Transient elastography (TE) has received increasing attention as a means to evaluate disease progression in patients with chronic liver disease. AIM: To assess the value of TE for predicting the stage of fibrosis. METHODS: Liver biopsy and TE were performed in 150 consecutive patients with chronic hepatitis C-related hepatitis (92 men and 58 women, age 50.6 (SD 12.5) years on the same day. Necro-inflammatory activity and the degree of steatosis at biopsy were also evaluated. RESULTS: The areas under the curve for the prediction of significant fibrosis (> or = F2), advanced fibrosis (> or = F3) or cirrhosis were 0.91, 0.99 and 0.98, respectively. Calculation of multilevel likelihood ratios showed that values of TE < 6 or > or = 12, < 9 or > or = 12, and < 12 or > or = 18, clearly indicated the absence or presence of significant fibrosis, advanced fibrosis, and cirrhosis, respectively. Intermediate values could not be reliably associated with the absence or presence of the target condition. The presence of inflammation significantly affected TE measurements in patients who did not have cirrhosis (p<0.0001), even after adjusting for the stage of fibrosis. Importantly, TE measurements were not influenced by the degree of steatosis. CONCLUSIONS: TE is more suitable for the identification of patients with advanced fibrosis than of those with cirrhosis or significant fibrosis. In patients in whom likelihood ratios are not optimal and do not provide a reliable indication of the disease stage, liver biopsy should be considered when clinically indicated. Necro-inflammatory activity, but not steatosis, strongly and independently influences TE measurement in patients who do not have cirrhosis.


Subject(s)
Hepatitis C, Chronic/complications , Liver Cirrhosis/diagnostic imaging , Adult , Aged , Biopsy , Disease Progression , Elasticity , Elasticity Imaging Techniques/methods , Fatty Liver/complications , Fatty Liver/physiopathology , Female , Humans , Liver/pathology , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Male , Middle Aged , Severity of Illness Index , Ultrasonography, Interventional/methods
5.
Eur J Clin Invest ; 37(6): 509-15, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17537159

ABSTRACT

BACKGROUND: Chronic liver diseases are frequently complicated by portal hypertension, an important component of which is the increased intrahepatic vascular resistance, in part related to endothelial dysfunction. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is an established mediator and marker of endothelial dysfunction. We therefore investigated the possible implication of ADMA in chronic liver diseases-induced portal hypertension. MATERIALS AND METHODS: We studied 39 consecutive patients with compensated hepatitis C virus (HCV) related chronic liver diseases. All patients underwent hepatic venous pressure gradient (HVPG) measurement, and simultaneous blood sampling from the hepatic vein and the pulmonary artery, for ADMA and nitrite/nitrate (NOx) plasma level determinations. RESULTS: A positive correlation between HVPG and ADMA concentrations in hepatic veins (ADMA-h) was found (r = 0.77, P < 0.0001). Moreover, a negative correlation between HVPG and NOx concentrations in the hepatic veins (NO-h) (r = -0.50, P = 0.005), and between ADMA-h and NO-h was observed (r = -0.40, P = 0.02). ADMA concentrations in pulmonary artery (ADMA-p) (0.55 +/- 0.13 micromol L(-1)) were significantly higher than in hepatic veins (0.47 +/- 0.09 micromol L(-1)) (P < 0.0001). CONCLUSIONS: These results suggest that ADMA may play a pathophysiological role in portal hypertension by contributing to the relative intrahepatic NO deficiency typical of endothelial dysfunction.


Subject(s)
Arginine/analogs & derivatives , Hepatitis C, Chronic/complications , Hypertension, Portal/etiology , Liver Cirrhosis/physiopathology , Adult , Aged , Arginine/physiology , Case-Control Studies , Female , Hepatitis C, Chronic/physiopathology , Humans , Hypertension, Portal/physiopathology , Male , Middle Aged , Nitric Oxide/metabolism , Portal Pressure/physiology
6.
Dig Liver Dis ; 36(8): 539-46, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15334775

ABSTRACT

BACKGROUND: Ascites is one of the most frequent severe complications in patients with liver cirrhosis. The treatment of this chronic disease usually requires the prolonged use of albumin, frequently continued even after patients' discharge from the hospital. AIMS: Aim of the study was to define a consensus among Italian physicians with regard to the use of albumin in patients with decompensated cirrhosis and ascites. METHODS: The study adopted the Delphi technique to conduct the consensus activities. All controversial issues related to the use of albumin were identified by the experts' board and proposed to the 68 participating hepatology centres through two subsequent questionnaires. The questionnaires, returned by the specialists involved, were collected and the answers classified to verify the elements on which a consensus was reached. RESULTS: The home use of albumin can help to improve the patient's general conditions and well-being. About 77% of the experts involved considered likely that albumin administration could shorten hospital stays or could reduce the number of hospital admissions. The results of the study, along with a socioeconomic analysis, were presented to the Italian Drug Commission, which subsequently removed the specific hypoalbuminemia level as a prerequisite for having the drug reimbursed by the National Health Service. CONCLUSIONS: For an outpatient prescription, the hypoalbuminemia limit of 2.5 g/dl or less is not sufficient, while the decision whether to administer the drug requires the evaluation of patient's overall clinical conditions as an essential criterion for the prescription of a home treatment with albumin.


Subject(s)
Albumins/therapeutic use , Ascites/drug therapy , Delphi Technique , Liver Cirrhosis/drug therapy , Drug Prescriptions/standards , Humans , Insurance, Health, Reimbursement , Italy
8.
Dig Liver Dis ; 35(9): 660-3, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14563190

ABSTRACT

In patients with cirrhosis, ascites accumulates because of sodium retention, triggered by a reduction of the effective arterial blood volume, and imbalanced Starling forces in the splanchnic area due to portal hypertension and hypoalbuminemia. Albumin is the ideal plasma expander in this setting, since it ameliorates systemic and reneal haemodynamics, so reducing sodium retention, and increases oncotic pressure in the splanchnic compartment. In particular, albumin proved useful in patients treated with diuretics, as demonstrated by a randomised study performed at our Instituition in which 126 ascitic inpatients were treated according to a stepped-care diuretic regimen. In fact, patients receiving diuretics plus albumin (n = 63) had a higher cummulative rate of response (p < 0.05) and a shorter hospital stay (20 +/- 1 versus 24 +/- 2 days, p < 0.05) than those given diuretics alone. Treatment with albumin on an outpatient basis (25 g/week) resulted in a lower probability of developing ascites (p < 0.02 vs. patients not given albumin) and a lower probability of readmission (p < 0.02). Patients given albumin also had a better quality of life. As discussed in another article, evidence also supports the use of albumin in patients treated for paracentesis, as well as in patients with spontaneous peritonitis or hepatorenal syndrome.


Subject(s)
Albumins/therapeutic use , Liver Cirrhosis/drug therapy , Ascites/drug therapy , Ascites/etiology , Diuretics/therapeutic use , Drug Therapy, Combination , Humans , Liver Cirrhosis/complications , Randomized Controlled Trials as Topic
9.
Dig Liver Dis ; 34(8): 592-605, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12502217

ABSTRACT

Ascites is the most common complication occurring during liver cirrhosis. Even if a significant decrease in renal clearance may be observed in the first step of chronic active liver disease, renal impairment, at times complicated by the typical signs of hepatorenal syndrome, occurs only in patients with ascites, especially when tense and refractory. Experimental and clinical data seem to suggest a primary sodium and water retention in the pathogenesis of ascites, in the presence of an intrahepatic increase of hydrostatic pressure, which, by itself, physiologically occurs during digestion. Abnormal sodium and water handling leads to plasma volume expansion, followed by decreased peripheral vascular resistance and increased cardiac output. This second step is in agreement with the peripheral arterial vasodilation hypothesis, depicted by an increase in total blood volume, but with a decreased effective arterial blood volume. This discrepancy leads to the activation of the sympathetic nervous and renin-angiotensin-aldosterone systems associated with the progressive activation of the renal autacoid systems, especially, that of the arachidonic acid. During advanced cirrhosis, renal impairment becomes more sustained and renal autacoid vasodilating substances are less available, possibly due to a progressive exhaustion of these systems. At the same time ascites becomes refractory inasmuch as it is no longer responsive to diuretic treatment. Various pathogenetic mechanisms leading to refractory ascites are mentioned. Finally, several treatment approaches to overcome the reduced effectiveness of diuretic therapy are cited. Paracentesis, together with simultaneous administration of human albumin or other plasma expanders is the main common approach to treat refractory ascites and to avoid a further decrease in renal failure. Other effective tools are: administration of terlipressin together with albumin, implantation of the Le Veen shunt, surgical porto-systemic shunting or transjugular intrahepatic portosystemic stent-shunt, or orthotopic liver transplantation, according to the conditions of the individual patient.


Subject(s)
Ascites , Hepatorenal Syndrome , Ascites/etiology , Ascites/physiopathology , Ascites/therapy , Hepatorenal Syndrome/etiology , Hepatorenal Syndrome/physiopathology , Hepatorenal Syndrome/therapy , Humans
10.
Histopathology ; 39(4): 373-81, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11683937

ABSTRACT

AIMS: Despite the importance of dendritic cells in stimulating primary and secondary immune responses by presenting antigens to T-lymphocytes in draining lymph nodes and peripheral tissues, respectively, very limited information is available on the presence and localization of these cells in hepatitis C virus (HCV)-related chronic active hepatitis. Therefore, we addressed the ultrastructure, immunophenotype, distribution and relationships to lymphatics of dendritic cells in portal infiltrates of this disease. METHODS AND RESULTS: Part of percutaneous diagnostic liver biopsies (Knodell's histological assessment index: 9-13) was processed for electron microscopy and for immunohistochemical detection of immune system cell membrane antigens and of the lymphatic endothelium marker podoplanin. In portal infiltrates, cells with electron microscopical and cell marker features of dendritic cells and expressing the activation markers CD54, CD80, CD83 and CD86 were organized in a discontinuous network, that embedded CD8+ lymphocytes in close contact with dendritic cells and came in contact with hepatocytes, sometimes infiltrating beyond the limiting plate. Also, dendritic cells were found within newly formed lymphatic capillaries in thin, infiltrated septa among hepatocytes. CONCLUSIONS: This evidence strongly suggests a critical role of dendritic cells and newly formed lymphatics in the pathogenesis and organization of the immune infiltrate that characterizes HCV-related chronic active hepatitis.


Subject(s)
CD8-Positive T-Lymphocytes/pathology , Dendritic Cells/pathology , Hepatitis C, Chronic/pathology , Liver/pathology , Adult , Aged , Antigens, CD/analysis , B7-1 Antigen/analysis , B7-2 Antigen , Female , Hepatitis C, Chronic/metabolism , Histocompatibility Antigens Class II/analysis , Humans , Immunoglobulins/analysis , Immunohistochemistry , Intercellular Adhesion Molecule-1/analysis , Liver/chemistry , Liver/ultrastructure , Male , Membrane Glycoproteins/analysis , Microscopy, Electron , Microscopy, Fluorescence , Middle Aged , CD83 Antigen
12.
J Biol Chem ; 276(13): 9945-54, 2001 Mar 30.
Article in English | MEDLINE | ID: mdl-11136732

ABSTRACT

Hepatic stellate cells (HSC) and glomerular mesangial cells (MC) are tissue-specific pericytes involved in tissue repair, a process that is regulated by members of the chemokine family. In this study, we explored the signal transduction pathways activated by the chemokine receptor CXCR3 in vascular pericytes. In HSC, interaction of CXCR3 with its ligands resulted in increased chemotaxis and activation of the Ras/ERK cascade. Activation of CXCR3 also stimulated Src phosphorylation and kinase activity and increased the activity of phosphatidylinositol 3-kinase and its downstream pathway, Akt. The increase in ERK activity was inhibited by genistein and PP1, but not by wortmannin, indicating that Src activation is necessary for the activation of the Ras/ERK pathway by CXCR3. Inhibition of ERK activation resulted in a decreased chemotactic and mitogenic effect of CXCR3 ligands. In MC, which respond to CXCR3 ligands with increased DNA synthesis, CXCR3 activation resulted in a biphasic stimulation of ERK activation, a pattern similar to the one observed in HSC exposed to platelet-derived growth factor, indicating that this type of response is related to the stimulation of cell proliferation. These data characterize CXCR3 signaling in pericytes and clarify the relevance of downstream pathways in the modulation of different biologic responses.


Subject(s)
Blood Vessels/cytology , Mitogen-Activated Protein Kinases/metabolism , Pericytes/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Protein Serine-Threonine Kinases , Receptors, Chemokine/metabolism , Signal Transduction , ras Proteins/metabolism , Androstadienes/pharmacology , Antineoplastic Agents/pharmacology , Blotting, Western , Cell Division , Cell Movement , Cells, Cultured , Chemotaxis , DNA/biosynthesis , Dose-Response Relationship, Drug , Enzyme Activation , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Flow Cytometry , Genistein/pharmacology , Humans , Ligands , Liver/cytology , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Pericytes/cytology , Phosphoprotein Phosphatases/pharmacology , Phosphorylation , Protein Binding , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Receptors, CXCR3 , Receptors, Chemokine/chemistry , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Time Factors , Wortmannin , src-Family Kinases/metabolism
13.
Gastroenterology ; 119(2): 479-92, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10930383

ABSTRACT

BACKGROUND & AIMS: Nitrovasodilators have been proposed for the treatment of portal hypertension alone or in combination with beta-blockers. In addition to their vasodilatory properties, nitric oxide (NO) donors may exert direct antifibrogenic properties. We evaluated the effect of nitroglycerin (NTG) and S-nitroso-N-acetyl penicillamine (SNAP) on the mitogenic and chemotactic properties of platelet-derived growth factor (PDGF)-BB and the modulation of the relative intracellular signaling pathways in fully activated human hepatic stellate cells (HSCs), a cell type that plays an active role in liver fibrogenesis and portal hypertension. METHODS & RESULTS: Both NTG and SNAP induced a dose-dependent decrease in PDGF-induced DNA synthesis and cell migration, which was associated with a decrease in PDGF-induced intracellular Ca(2+) increase and extracellular signal-regulated kinase (ERK) activity. These effects were not related to activation of the classic soluble guanylate cyclase (sGC)/guanosine 3',5'-cyclic monophosphate pathway; accordingly, Western blot analysis of HSC lysates revealed the absence of the alpha(1)beta(1) ubiquitous subunits of sGC, whereas they were detectable in quiescent HSCs, freshly isolated from normal human liver. Conversely, both NTG and SNAP induced a more than 10-20-fold increase in prostaglandin E(2) in cell supernatants within 1 minute, associated with an increase in intracellular adenosine 3',5'-cyclic monophosphate levels. Accordingly, the inhibitory effects of NO donors on PDGF action and signaling were eliminated after preincubation with ibuprofen. CONCLUSIONS: These results suggest that NO donors may exert a direct antifibrogenic action by inhibiting proliferation, motility, and contractility of HSCs in addition to a reduction of fibrillar extracellular matrix accumulation.


Subject(s)
Cell Movement/drug effects , Liver/cytology , Nitroglycerin/pharmacology , Platelet-Derived Growth Factor/pharmacology , Vasodilator Agents/pharmacology , Calcium/metabolism , Cell Division/drug effects , Cells, Cultured , Chemotaxis/drug effects , Cyclic GMP/metabolism , Dinoprostone/metabolism , Guanylate Cyclase/metabolism , Hemostatics/pharmacology , Humans , Liver/enzymology , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Signal Transduction/drug effects , Thrombin/pharmacology , Type C Phospholipases/metabolism
14.
Gastroenterology ; 119(2): 466-78, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10930382

ABSTRACT

BACKGROUND & AIMS: Proliferation and migration of hepatic stellate cells (HSCs) and expression of chemokines are involved in the pathogenesis of liver inflammation and fibrogenesis. Peroxisome proliferator-activated receptor (PPAR)-gamma is a receptor transcription factor that controls growth and differentiation in different tissues. We explored the effects of PPAR-gamma agonists on the biological actions of cultured human HSCs. METHODS: HSCs were isolated from normal human liver tissue and used in their myofibroblast-like phenotype or immediately after isolation. Activation of PPAR-gamma was induced with 15-deoxy-Delta(12, 14)-prostaglandin J(2) or with troglitazone. RESULTS: PPAR-gamma agonists dose-dependently inhibited HSC proliferation and chemotaxis induced by platelet-derived growth factor. This effect was independent of changes in postreceptor signaling or expression of c-fos and c-myc and was associated with inhibition of cell cycle progression beyond the G(1) phase. Activation of PPAR-gamma also resulted in a complete inhibition of the expression of monocyte chemotactic protein 1 at the gene and protein levels. Comparison of quiescent and culture-activated HSCs revealed a marked decrease in PPAR-gamma expression in activated cells. CONCLUSIONS: Activation of PPAR-gamma modulates profibrogenic and proinflammatory actions in HSCs. Reduced PPAR-gamma expression may contribute to confer an activated phenotype to HSCs.


Subject(s)
Hepatitis/metabolism , Liver Cirrhosis/metabolism , Liver/cytology , Liver/immunology , Receptors, Cytoplasmic and Nuclear/metabolism , Thiazolidinediones , Transcription Factors/metabolism , Antineoplastic Agents/pharmacology , Biological Transport/drug effects , Biological Transport/immunology , Cell Division/immunology , Cell Movement/immunology , Cell Survival/drug effects , Cells, Cultured , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Chromans/pharmacology , Cytotoxins/metabolism , Gene Expression/immunology , Hepatitis/immunology , Hepatitis/pathology , Humans , Interleukin-1/pharmacology , Ligands , Liver/metabolism , Liver Cirrhosis/immunology , Liver Cirrhosis/pathology , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Phosphorylation , Platelet-Derived Growth Factor/metabolism , Prostaglandin D2/analogs & derivatives , Prostaglandin D2/pharmacology , Proto-Oncogenes/genetics , RNA, Messenger/analysis , Thiazoles/pharmacology , Transcription Factor AP-1/metabolism , Troglitazone , Tyrosine/metabolism , Wound Healing/immunology , p38 Mitogen-Activated Protein Kinases
15.
Hepatology ; 31(1): 131-40, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10613738

ABSTRACT

Focal adhesion kinase (FAK) is a widely expressed nonreceptor tyrosine kinase found in focal adhesions. FAK has been indicated as a point of convergence of other signaling pathways including platelet-derived growth factor (PDGF) receptors, and recently, FAK tyrosine phosphorylation has been shown to be stimulated by PDGF. In the present study we assessed the role of Ras as a possible intermediate protein regulating PDGF-induced FAK tyrosine phosphorylation in human hepatic stellate cells (HSCs), liver-specific pericytes primarily involved in the pathogenesis of liver fibrosis. For this purpose, cells were first subjected to retroviral-mediated gene transfer with a dominant-negative mutant of Ras (N17Ras). This resulted in a marked inhibition of PDGF-induced FAK tyrosine phosphorylation together with the expected reduction of PDGF-induced extracellular signal-regulated kinase activity (ERK). Afterward, the effects of pharmacological agents potentially affecting Ras isoprenylation were evaluated. PDGF-induced FAK tyrosine phosphorylation, ERK activity and intracellular calcium increase, as well as the biological effects of this growth factor, (i.e., mitogenesis and cell migration) were effectively blocked by GGTI-298, an inhibitor of geranylgeranyltransferase I. Inhibition of Ras processing obtained with FTI-277, an inhibitor of farnesyltransferase, resulted in detectable effects only at high doses. Taken together, these results establish that Ras operates as a protein-linking PDGF-beta receptor to FAK in human HSCs, and that signaling molecules requiring geranylgeranylation may also be involved in this process.


Subject(s)
Cell Adhesion Molecules/metabolism , Liver/enzymology , Phosphotyrosine/metabolism , Platelet-Derived Growth Factor/pharmacology , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins p21(ras)/physiology , Alkyl and Aryl Transferases/antagonists & inhibitors , Becaplermin , Calcium/metabolism , Cell Adhesion Molecules/analysis , Cells, Cultured , Enzyme Inhibitors/pharmacology , Farnesyltranstransferase , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Humans , Mitogen-Activated Protein Kinase 1/metabolism , Mutation , Phosphorylation , Protein Prenylation , Protein-Tyrosine Kinases/analysis , Proto-Oncogene Proteins c-sis , Proto-Oncogene Proteins p21(ras)/genetics , Receptors, Platelet-Derived Growth Factor/analysis , Receptors, Platelet-Derived Growth Factor/metabolism , Signal Transduction , Transfection , Type C Phospholipases/metabolism
16.
J Hepatol ; 31(6): 1053-61, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10604579

ABSTRACT

BACKGROUND/AIMS: Protooncogenes may play an important role, not only in carcinogenesis, but also in the regulation of normal cellular proliferation and differentiation. Several studies have indicated increased expression of the Ras protooncogenes in the liver in animal models and in patients with liver cirrhosis. The aim of the present study was to examine whether a synthetic Ras antagonist, S-farnesylthiosalicylic acid (FTS), which specifically dislodges Ras from the membrane of Ras-transformed fibroblasts (EJ cells), can prevent experimentally-induced liver cirrhosis in rats. METHODS: Cirrhosis was induced in male Wistar rats by intraperitoneal administration of thioacetamide (200 mg/kg twice weekly for 12 weeks). The Ras antagonist, farnesylthiosalicylic acid (FTS, 5 mg/kg), was administered during the study period 3 times a week. Ras expression in the liver was determined by Western blot analysis with pan anti-Ras antibodies and by immunohistochemistry. RESULTS: Rats treated with thioacetamide and the Ras antagonist, farnesylthiosalicylic acid (FTS), for 12 weeks had lower histopathologic scores of fibrosis and inflammation (p-values of 0.003 and 0.008, respectively) than those treated with thioacetamide only. There were no differences between the histopathologic scores in vehicle (control) and in Ras-antagonist (FTS) only treatments. Analysis of hepatic hydroxyproline levels from the two thioacetamide-treated groups and controls confirmed the histopathologic scores (7.7+/-0.9 mg/g protein in the TAA-treated vs. 3.8+/-0.5 mg/g protein in the TAA+FTS treated group, p = 0.007). Ras levels, determined by Western blot analysis, were markedly increased in the livers treated with TAA (17-fold over control) and significantly decreased (by about 70%) in the livers of rats treated with TAA and FTS. Studies in isolated human hepatic stellate cells demonstrated that FTS inhibited both DNA synthesis and migration of those cells (p<0.05). CONCLUSION: These results indicate that inhibition of Ras expression in the liver during fibrogenesis, prevents the development of experimentally-induced hepatic cirrhosis.


Subject(s)
Antineoplastic Agents/therapeutic use , Enzyme Inhibitors/therapeutic use , Farnesol/analogs & derivatives , Liver Cirrhosis, Experimental/drug therapy , Salicylates/therapeutic use , ras Proteins/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Farnesol/pharmacology , Farnesol/therapeutic use , Humans , Male , Rats , Rats, Wistar , Salicylates/pharmacology
18.
Hepatology ; 30(4): 951-8, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10498647

ABSTRACT

Upon liver injury, hepatic stellate cells (HSC) show increased proliferation, motility, and extracellular matrix (ECM) production. The extracellular signal-regulated kinases (ERK) control different functions in a cell-specific manner. In this study, we evaluated the role of ERK activation in cultured HSC stimulated with platelet-derived growth factor (PDGF) and after induction of liver injury in vivo. HSC were isolated from normal human liver tissue, cultured on plastic, and used in their myofibroblast-like phenotype. In in vivo experiments, HSC were isolated from normal rats or at different time points after a single intragastric administration of CCl(4). Nontoxic concentrations of PD98059, a specific inhibitor of ERK activation, reduced PDGF-induced activation of ERK in a dose-dependent fashion. Suppression of ERK activation was associated with complete inhibition of HSC proliferation and with a 57% reduction in chemotaxis. In the presence of the ERK inhibitor, binding of the AP-1 complex and of STAT1 to the related regulatory elements was inhibited. The inhibition of the DNA binding activity of STAT1 was mediated by a reduction in PDGF-induced tyrosine phosphorylation. Expression of c-fos in response to PDGF was also reduced, but not suppressed, by treatment with PD98059. In HSC isolated from CCl(4)-treated rats, ERK activity increased as early as 6 hours following liver damage, and declined thereafter. The results of this study indicate that ERK activation regulates proliferation and chemotaxis of HSC, and modulates nuclear signaling. Acute liver damage in vivo leads to activation of ERK in HSC.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Liver Diseases/enzymology , Liver/physiology , Platelet-Derived Growth Factor/physiology , Animals , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Calcium-Calmodulin-Dependent Protein Kinases/physiology , Carbon Tetrachloride , Cell Division/physiology , Cell Movement/physiology , Cell Nucleus/physiology , Chemical and Drug Induced Liver Injury , Enzyme Activation/physiology , Enzyme Induction , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Humans , Liver/cytology , Liver/pathology , Proto-Oncogene Proteins c-fos/metabolism , Rats , Signal Transduction/drug effects , Time Factors
19.
Eur J Gastroenterol Hepatol ; 11(9): 1061-5, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10503849

ABSTRACT

The pathogenesis of ascites, a severe and the most frequent complication during cirrhosis, is still not completely understood, but present evidence indicates that portal hypertension principally triggers renal sodium and water retention. Ascites is associated with profound disturbances of splanchnic and systemic haemodynamics, which in turn may influence renal function. Within the kidney the balance between vasoconstricting and vasodilating factors is critical for the maintenance of renal function. As the disease progresses, vasoconstricting factors (mainly angiotensin II, catecholamines, thromboxane, leucotrienes and endothelins) prevail, probably due to the exhaustion of the vasodilating renal autacoid system (mainly prostaglandins). In this setting, vasoconstriction of the intrarenal vascular system induces marked and often irreversible sodium and water retention, leading to refractory ascites, a progressive rise in plasma creatinine levels and reduction of renal clearances (hepatorenal syndrome, HRS). This persistent renal hypoxia may also favour the occurrence of tubular damage due to several causes. A careful therapeutic approach is first based on sequential diuretic treatment (and the addition of adequate plasma expansion with human albumin for patients with diuretic resistant ascites), which may lead to control of ascites for years. However, when HRS occurs, all the proposed treatments (such as paracentesis, administration of renal vasodilators, systemic vasoconstrictors, calcium channel antagonists, TIPS, surgical portosystemic shunts) have been shown to moderately or temporarily improve renal function only, leaving liver transplantation as the only choice of treatment for patients.


Subject(s)
Angiotensin II/antagonists & inhibitors , Ascites/therapy , Diuretics/therapeutic use , Hepatorenal Syndrome/therapy , Ascites/etiology , Hemodynamics , Hepatorenal Syndrome/etiology , Humans , Liver Cirrhosis/complications , Liver Transplantation
20.
J Hepatol ; 30(4): 632-8, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10207804

ABSTRACT

BACKGROUND/AIMS: The aim of this study was to evaluate cardiovascular and renal function in patients with compensated cirrhosis and essential hypertension in the supine position and in response to standing up. METHODS: Twenty-four patients with compensated cirrhosis (12 with elevated arterial pressure) and 20 healthy volunteers underwent echocardiographic evaluation of left ventricular end-diastolic and stroke volumes, ejection fraction, cardiac index, arterial pressure, peripheral resistance, creatinine clearance and sodium excretion in both the supine and the standing position. RESULTS: When supine, only normotensive patients had a hyperdynamic circulation, with increased left ventricular end-diastolic and stroke volumes, cardiac index, and ejection fraction, and reduced peripheral resistance. Creatinine clearance and sodium excretion were comparable in patients and controls. Standing induced a decrease in end-diastolic volume in all subjects. Healthy volunteers maintained cardiovascular homeostasis by increasing ejection fraction and heart rate, while both normotensive and hypertensive cirrhotic patients experienced a fall in stroke volume and cardiac index, despite a marked activation of the renin-aldosterone and sympathetic nervous system. Creatinine clearance decreased only in normotensive patients, who experienced the greatest reduction in sodium excretion. CONCLUSIONS: Compensated cirrhotic patients with arterial hypertension had no evidence of hyperdynamic circulation. Like their normotensive counterparts, hypertensive patients had an impaired cardiovascular response to the postural challenge, but a lesser degree of renal dysfunction during standing.


Subject(s)
Creatinine/metabolism , Hemodynamics/physiology , Hypertension/physiopathology , Liver Cirrhosis/physiopathology , Aged , Blood Pressure , Esophageal and Gastric Varices/etiology , Female , Heart Rate , Humans , Hypertension/complications , Hypertension, Renal/etiology , Kidney Function Tests , Liver Cirrhosis/complications , Male , Middle Aged , Multivariate Analysis , Posture , Reference Values , Sodium/blood , Stroke Volume , Supine Position , Vascular Resistance , Ventricular Function, Left
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