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1.
Gut ; 58(4): 582-4, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19299387

RESUMO

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.


Assuntos
Stents Farmacológicos/efeitos adversos , Isquemia/etiologia , Falência Hepática/etiologia , Fígado/irrigação sanguínea , Derivação Portossistêmica Transjugular Intra-Hepática/efeitos adversos , Humanos , Isquemia/diagnóstico , Falência Hepática/diagnóstico , Masculino , Pessoa de Meia-Idade , Politetrafluoretileno , Derivação Portossistêmica Transjugular Intra-Hepática/instrumentação , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler
2.
Gut ; 57(9): 1288-93, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18448567

RESUMO

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.


Assuntos
Hepatite C Crônica/complicações , Cirrose Hepática/diagnóstico por imagem , Adulto , Idoso , Biópsia , Progressão da Doença , Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Fígado Gorduroso/complicações , Fígado Gorduroso/fisiopatologia , Feminino , Humanos , Fígado/patologia , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Ultrassonografia de Intervenção/métodos
3.
FEBS Lett ; 414(2): 221-5, 1997 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-9315690

RESUMO

We investigated whether activation of integrin receptors could modulate the expression of monocyte chemotactic protein-1 (MCP-1) in human hepatic stellate cells (HSC), mesenchymal cells responsible for extracellular matrix synthesis within the liver. When compared to non-adherent cells, HSC plated on collagen types I or IV, or fibronectin, showed increased MCP-1 gene expression and protein secretion in the conditioned medium. Increased MCP-1 secretion was also observed when cells were plated on dishes coated with a monoclonal antibody directed against the beta1-integrin subunit, demonstrating that ligation of beta1-integrins is sufficient to stimulate MCP-1 expression. Conversely, integrin-independent cell adhesion on poly-L-lysine did not modify MCP-1 secretion. Disruption of the actin cytoskeleton by cytochalasin D blocked the collagen-dependent increase in MCP-1 secretion. Chemotactic assay of HSC-conditioned medium showed that HSC plated on collagen secrete higher amounts of chemotactic factors for lymphomonocytes, and that MCP-1 accounts for the great majority of this effect. These findings indicate a novel mechanism of MCP-1 regulation possibly relevant in those conditions where HSC interact with an altered extracellular matrix.


Assuntos
Quimiocina CCL2/biossíntese , Matriz Extracelular/fisiologia , Integrinas/fisiologia , Leucócitos Mononucleares/fisiologia , Fígado/citologia , Fígado/fisiologia , Adesão Celular , Células Cultivadas , Quimiotaxia de Leucócito , Colágeno , Fibronectinas , Regulação da Expressão Gênica , Humanos , Técnicas In Vitro , Mesoderma/citologia , Mesoderma/fisiologia , Reprodutibilidade dos Testes
4.
Br J Pharmacol ; 122(6): 1047-54, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9401768

RESUMO

1. Pentoxifylline (PTF) may act as a potential antifibrogenic agent by inhibiting cell proliferation and/or collagen deposition in cell type(s) responsible for the accumulation of extracellular matrix. The aim of the present study was to investigate at which level PTF may affect synthesis and degradation of type I collagen in human hepatic stellate cells (HSCs), a key source of connective tissue in fibrotic liver. 2. Procollagen type I synthesis and release were evaluated in cells maintained in serum free/insulin free medium for 48 h and then stimulated with transforming growth factor-beta 1 (TGF-beta 1) for different time periods in the presence or absence of PTF. TGF-beta 1 caused an upregulation of procollagen I mRNA levels with a peak increase after 3-6 h of stimulation. This effect was followed by an increase in both the cell associated and the extracellular levels of the corresponding protein, with a peak effect at 9-12 h after the addition of TGF-beta 1. Co-incubation with PTF slightly but consistently reduced basal as well as stimulated procollagen I mRNA levels, with negligible effects on the cell-associated expression of the corresponding protein. Conversely, PTF dose-dependently reduced procollagen type I levels detected in supernatants from unstimulated and stimulated cells. 3. Pulse-chase experiments employing L-[3H]-proline revealed that PTF was able to induce significantly the degradation of procollagen, mainly in the extracellular compartment. We next analysed the effect of PTF on the major pathway involved in type I collagen degradation. PTF did not affect the expression of metalloproteinase 1 (MMP-1) mRNA both in basal and stimulated conditions, whereas it markedly reduced the expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) mRNA. Accordingly incubation with PTF increased the levels of 'activated MMP-1' in cell supernatants in both basal and stimulated conditions. 4. These results suggest that the antifibrogenic action of PTF on human HSCs is mainly mediated by extracellular collagen degradation rather than by a reduction of collagen synthesis.


Assuntos
Fígado/efeitos dos fármacos , Pentoxifilina/farmacologia , Pró-Colágeno/metabolismo , Fatores de Crescimento Transformadores/farmacologia , Células Cultivadas , Colagenases/genética , Espaço Extracelular/metabolismo , Humanos , Hidrólise , Fígado/citologia , Fígado/metabolismo , Metaloproteinase 1 da Matriz , Pró-Colágeno/genética , RNA Mensageiro/genética , Inibidor Tecidual de Metaloproteinase-1/genética
5.
Eur J Gastroenterol Hepatol ; 11(9): 1061-5, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10503849

RESUMO

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.


Assuntos
Angiotensina II/antagonistas & inibidores , Ascite/terapia , Diuréticos/uso terapêutico , Síndrome Hepatorrenal/terapia , Ascite/etiologia , Hemodinâmica , Síndrome Hepatorrenal/etiologia , Humanos , Cirrose Hepática/complicações , Transplante de Fígado
6.
Dig Liver Dis ; 35(9): 660-3, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14563190

RESUMO

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.


Assuntos
Albuminas/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Ascite/tratamento farmacológico , Ascite/etiologia , Diuréticos/uso terapêutico , Quimioterapia Combinada , Humanos , Cirrose Hepática/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Dig Liver Dis ; 34(8): 592-605, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12502217

RESUMO

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.


Assuntos
Ascite , Síndrome Hepatorrenal , Ascite/etiologia , Ascite/fisiopatologia , Ascite/terapia , Síndrome Hepatorrenal/etiologia , Síndrome Hepatorrenal/fisiopatologia , Síndrome Hepatorrenal/terapia , Humanos
8.
Dig Liver Dis ; 36(8): 539-46, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15334775

RESUMO

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.


Assuntos
Albuminas/uso terapêutico , Ascite/tratamento farmacológico , Técnica Delphi , Cirrose Hepática/tratamento farmacológico , Prescrições de Medicamentos/normas , Humanos , Reembolso de Seguro de Saúde , Itália
9.
Ann Ital Med Int ; 8 Suppl: 23S-35S, 1993 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-8117519

RESUMO

The present review firstly gives some details regarding nosological approach to the cholestatic syndrome. In addition, different steps are considered, identifying 12 possible metabolic defects responsible for determining a cholestatic syndrome either in man or in experimental conditions. Eleven defects out of these 12 steps should be considered related to the structure and function of the hepatocyte, whereas the twelfth one, which comprises 3 different sub-groups, is based on a mechanical obstructive mechanism, localized exclusively into the liver parenchyma, thus resembling the other ones included in the chapter of intrahepatic cholestasis.


Assuntos
Colestase Intra-Hepática/etiologia , Bile/metabolismo , Colestase Intra-Hepática/fisiopatologia , Humanos , Fígado/fisiopatologia , Fígado/ultraestrutura
10.
Ann Ital Med Int ; 11 Suppl 2: 23S-29S, 1996 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-9004817

RESUMO

The role of hepatitis B virus (HBV) and hepatitis C virus (HCV) as a major cause of chronic liver disease is now accepted worldwide. This study was aimed at evaluating the natural history of the disease in patients with virus-induced chronic active hepatitis or cirrhosis, and the influence played by age, sex and etiology, liver function tests and by the occurrence of different complications. We retrospectively examined the clinical records of 506 inpatients: 194 were affected by chronic active hepatitis (125 males, 69 females, mean age 45 +/- 11 years, 146 HCV- and 48 HBV-related), and 312 by cirrhosis without clinical evidence of portal hypertension (178 males, 134 females, mean age 53 +/- 9 years, 249 HCV- and 63 HBV-related). The occurrence of cirrhosis in the chronic active hepatitis group was then calculated, together with the occurrence of complications and the cumulative mortality rate of established cirrhosis. During follow-up 93 patients with chronic hepatitis developed cirrhosis. The cumulative probability of developing cirrhosis in this group was 6.64% at 5 years, 56.1% at 10 years and 86.8% at 15 years. These patients were therefore included in the cirrhosis group for the final analysis, so that a total of 405 cirrhotic patients were evaluated: these patients had a cumulative survival rate of 99.1% at 5, 76.8% at 10 and 49.4% at 15 years. Comparing the age-adjusted death rate of our patients with the general Italian population, we observed that in patients with liver cirrhosis it was 3.14 and 2.84 times higher in men and women, respectively. Bilirubin was an independent indicator of survival. Several complications, such as esophageal varices, ascites, jaundice, hemorrhage, hepatic encephalopathy and hepatocellular carcinoma significantly reduced the survival rate and were indicated as major complications, while thrombocytopenia, cholelithiasis and diabetes did not affect survival and thus were called minor complications. Incidence of hepatocellular carcinoma was very high especially in males, without correlation with etiology. In conclusion, the progression of virus-induced chronic active hepatitis to cirrhosis is not influenced by sex and etiology. Similarly, the different etiology does not modify the natural history of cirrhosis while the occurrence of one or more major complications significantly shortens survival. The longer survival rate observed in patients with cirrhosis included in this study is probably due to the selective inclusion of patients with early disease and no evidence of portal hypertension.


Assuntos
Hepatite Viral Humana/complicações , Cirrose Hepática/complicações , Cirrose Hepática/virologia , Adulto , Ascite/etiologia , Carcinoma Hepatocelular/etiologia , Varizes Esofágicas e Gástricas/etiologia , Feminino , Hemorragia Gastrointestinal/etiologia , Encefalopatia Hepática/etiologia , Humanos , Icterícia/etiologia , Cirrose Hepática/mortalidade , Cirrose Hepática/fisiopatologia , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida
11.
Braz Dent J ; 8(2): 99-104, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9590933

RESUMO

The aim of this study was to verify the association between children and their mothers (N = 28) for periodontal clinical and microbiological measures. Periodontal clinical parameters (probing depth and bleeding on probing) were obtained from six reference teeth from each mother-child pair. In addition, subgingival plaque samples taken from the same reference teeth were collected and placed on the Perioscan test for the detection of Treponema denticola, Porphyromonas gingivalis and Bacteroides forsythus. There were statistically significant differences between children and mothers regarding probing depth; there was an overall tendency for mothers to exhibit average probing depths greater than their children. In contrast, if a child had a bleeding site, the respective site on the mother usually also bled on probing, implying that there was an association in terms of bleeding between the mother-child pairs. Similar findings were observed for the Perioscan test. It is concluded that the occurrence of bleeding and periodontal anaerobic infections (as determined by the Perioscan test) were similar in reference teeth of mother-child pairs. These data suggest that parents with periodontal disease may serve as a reservoir of periodontopathic organisms for their children.


Assuntos
Bolsa Periodontal/diagnóstico , Adulto , Bacteroides/isolamento & purificação , Distribuição de Qui-Quadrado , Criança , Placa Dentária/diagnóstico , Placa Dentária/etiologia , Placa Dentária/microbiologia , Feminino , Humanos , Masculino , Índice Periodontal , Bolsa Periodontal/etiologia , Bolsa Periodontal/microbiologia , Periodonto/microbiologia , Porphyromonas gingivalis/isolamento & purificação , Treponema/isolamento & purificação
12.
Case Rep Oncol ; 7(1): 92-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24575023

RESUMO

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.

14.
Eur J Clin Invest ; 37(6): 509-15, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17537159

RESUMO

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.


Assuntos
Arginina/análogos & derivados , Hepatite C Crônica/complicações , Hipertensão Portal/etiologia , Cirrose Hepática/fisiopatologia , Adulto , Idoso , Arginina/fisiologia , Estudos de Casos e Controles , Feminino , Hepatite C Crônica/fisiopatologia , Humanos , Hipertensão Portal/fisiopatologia , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Pressão na Veia Porta/fisiologia
15.
Gastroenterology ; 112(2): 522-31, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9024306

RESUMO

BACKGROUND & AIMS: Hepatic stellate cells (HSCs) play a key role in the development of liver fibrosis. Integrin receptors contribute to the regulation cell adhesion and migration. The aim of this study was to evaluate the interaction between focal adhesion kinase (FAK) and phospholipase C gamma (PLC gamma) potentially involved in HSC integrin-mediated signaling pathways. METHODS: Interaction between FAK and PLC gamma was determined by immunoprecipitation and immunoblotting. HSC chemotactic activity was evaluated using the Boyden chamber technique. RESULTS: HSC adhesion to extracellular matrix components (collagen type I and IV, laminin, and fibronectin) and antibody-mediated beta 1 ligation elicited increased tyrosine phosphorylation of FAK. HSC adhesion to different extracellular matrix components did not result in PLC gamma tyrosine phosphorylation. However, HSC adhesion induced association between PLC gamma and FAK. All extracellular matrix components tested stimulated HSC chemotactic activity only at high concentrations. On the contrary, platelet-derived growth factor, homodimer BB (PDGF-BB), was able to stimulate HSC migration in a dose-dependent manner; this event, occurring in the presence of FAK phosphorylation, was associated to a dose-dependent PLC gamma tyrosine phosphorylation. CONCLUSIONS: These findings provide the first evidence that PLC gamma recruitment by FAK during HSC adhesion is an important process implicating a link between integrin and PDGF-mediated signaling pathways to regulate HSC adhesion and motility.


Assuntos
Moléculas de Adesão Celular/fisiologia , Isoenzimas/fisiologia , Fígado/metabolismo , Proteínas Tirosina Quinases/fisiologia , Fosfolipases Tipo C/fisiologia , Becaplermina , Adesão Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proteínas da Matriz Extracelular/fisiologia , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Integrina beta1/fisiologia , Isoenzimas/metabolismo , Fígado/citologia , Fosfolipase C gama , Fosforilação , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Proto-Oncogênicas c-sis , Proteínas Recombinantes , Fatores de Tempo , Fosfolipases Tipo C/metabolismo , Tirosina/metabolismo
16.
Cardiology ; 84 Suppl 2: 68-79, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7954548

RESUMO

In cirrhosis of the liver structural distortion of the sinusoidal vessels is the major factor responsible for the increase in portal venous pressure and the development of abdominal ascites. The mechanisms by which advanced cirrhosis of the liver leads to widespread changes in the systemic circulation including vasodilatation, increased cardiac output and expanded plasma volume, together with activation of a range of antinatriuretic and natriuretic factors, are unclear. Several hypotheses have been proposed to explain these pathophysiological consequences, including underfilling of the systemic arterial system, overflow and peripheral vasodilatation, with a decrease in effective arterial blood volume. The evidence for and against these hypotheses is critically examined. In patients with hepatic cirrhosis complicated by ascites, increased intrarenal release of vasodilating prostaglandins may assist in sustaining renal blood flow and glomerular filtration rate by counteracting the vasoconstrictor effects of noradrenaline and angiotensin II. In advanced stages of the syndrome, cirrhotic ascites may become refractory to medical treatment. In this situation renal function becomes progressively impaired and eventually acute renal failure, so-called hepatorenal syndrome, supervenes due to intense renal vasoconstriction and opening of intrarenal arteriovenous shunts. The progressive renal vasoconstriction may also be accentuated by the reduced synthesis of renal vasodilating prostaglandins. The medical treatment of ascites is based on bed-rest, a low-sodium diet and administration of aldosterone antagonists and loop diuretics. Patients who are refractory to such therapy may be further treated by paracentesis or by the LeVeen shunt, though the long-term results of these physical therapies are unsatisfactory.


Assuntos
Ascite/etiologia , Ascite/terapia , Cirrose Hepática/complicações , Humanos
17.
Gastroenterology ; 110(4): 1127-36, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8613002

RESUMO

BACKGROUND & AIMS: Human hepatic stellate cells (HSCs), liver-specific pericytes, are currently considered major producers of extracellular matrix (ECM) components and key elements in the development of liver fibrogenesis. However, little is known about the possible functional interactions between HSCs and the various ECM components. Therefore, the present study was designed to evaluate the expression of integrins, the major family of extracellular matrix receptors. METHODS: Integrin expression was evaluated by immunoprecipitation and confirmed by immunocytochemistry and flow cytometry. RESULTS: Human HSCs were shown to express alpha1beta1, alpha2beta1, alpha(v)beta1. Adhesion to type IV collagen, type I collagen, fibronectin, and laminin 1 was inhibited by anti-beta1 antibody identifying beta1-containing integrins as possible receptors for these components. In addition, we showed that HSCs express alpha6beta4, a heterodimer known to mediate adhesion of epithelial cells to laminin and not previously characterized in mesenchymal cells. Adhesion to laminin 1 was not inhibited by antibodies specific for alpha6 or beta4, thus establishing that laminin 1 is not a ligand for alpha6beta4 in this cell type. CONCLUSIONS: These findings represent the first description of integrin receptors in HSC and provide an attempt to cover the gap of information in the field of HSC-ECM interactions.


Assuntos
Adipócitos/metabolismo , Colágeno/metabolismo , Integrinas/metabolismo , Laminina/metabolismo , Fígado/metabolismo , Adipócitos/citologia , Adipócitos/imunologia , Adesão Celular , Células Cultivadas , Matriz Extracelular/imunologia , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Humanos , Imuno-Histoquímica , Fígado/citologia , Fígado/imunologia , Testes de Precipitina , Receptores de Colágeno , Receptores de Laminina/metabolismo
18.
Liver ; 8(6): 354-9, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3265171

RESUMO

In patients with chronic liver disease, the reliability of various criteria generally used to diagnose impaired glucose tolerance and diabetes was evaluated. Twenty-one patients with chronic persistent hepatitis, 68 patients with chronic active hepatitis and 57 patients with liver cirrhosis were studied. All subjects underwent an oral glucose tolerance test (75 g). Impaired glucose tolerance and diabetes were diagnosed according to the criteria established by: the National Diabetes Study Group; Fajans and Conn; the European Diabetes Study Group; Deutsche Diabetes Gesellschaft; Kobberling & Creutzfeld criteria 1 and 2; Wilkerson; and the University Group Diabetes Program. The results obtained are in partial agreement with other reported data, showing a high prevalence of both impaired glucose tolerance and diabetes in chronic liver disease, with a positive correlation to the severity of hepatic involvement. However, our results show that the agreement among the criteria most frequently used for diagnosing impaired glucose tolerance and diabetes is still far from satisfactory.


Assuntos
Complicações do Diabetes , Hepatopatias/complicações , Adulto , Idoso , Doença Crônica , Estudos Transversais , Diabetes Mellitus/diagnóstico , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Pessoa de Meia-Idade
19.
Gastroenterology ; 115(2): 433-42, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9679049

RESUMO

BACKGROUND & AIMS: Hepatocellular carcinoma is a common complication in liver cirrhosis. The integrin alpha6 beta1, a receptor for the laminin family of extracellular matrix proteins, has been found to be overexpressed in hepatocarcinoma. In an effort to further characterize the involvement of alpha6 beta1-integrin in hepatocarcinoma progression and to study alpha6 beta1-mediated functions, a human hepatocarcinoma cell line, HepG2, that express high surface levels of alpha6 beta1 and uses only this integrin to mediate adhesion on laminin was identified. METHODS: To assess the role of alpha6 beta1 in these cells, a cytoplasmic domain deletion mutant of the beta4-integrin subunit by complementary DNA transfection was expressed. The expression of the mutant beta4 subunit in association with endogenous alpha6 showed a dominant-negative effect on alpha6 beta1 expression. RESULTS: Stable transfectants of HepG2 that expressed the mutant beta4 subunit showed a reduced ability to adhere and migrate on laminin matrices and to invade Matrigel. Furthermore, transfected cells showed significantly lower growth rates and reduced anchorage-independent growth compared with mock-transfected cells. CONCLUSIONS: These findings on the expression and function of alpha6 beta1 in hepatocarcinoma cells emphasize the potential contribution of this laminin receptor in the neoplastic transformation of hepatocytes.


Assuntos
Carcinoma Hepatocelular/genética , Deleção de Genes , Integrinas/genética , Neoplasias Hepáticas/genética , Antígenos CD/genética , Antígenos CD/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Movimento Celular/fisiologia , Transformação Celular Neoplásica/genética , Humanos , Integrina alfa6beta1 , Integrina beta4 , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Invasividade Neoplásica/fisiopatologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fenótipo , Receptores de Laminina/metabolismo , Transfecção/fisiologia , Células Tumorais Cultivadas
20.
Cardiovasc Drugs Ther ; 7 Suppl 1: 81-5, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8435382

RESUMO

The effects of torasemide (20 mg/day) and furosemide (50 mg/day), each given over 4 days, were compared in a randomized and crossover study carried out in seven patients with cirrhosis and tense ascites. Patients also received a low-sodium (40 mmol/day) diet and the aldosterone antagonist, potassium canrenoate (100 mg b.i.d.). Torasemide induced a remarkably higher natriuretic (120 +/- 15 vs. 33 +/- 6 mmol/day, p < 0.02) and diuretic (1450 +/- 63 vs. 900 +/- 58 ml, p < 0.005) effect than furosemide. Body weight loss was also significantly higher (2.5 +/- 1.6 vs. 0.2 +/- 1.3 kg, p < 0.01) during the torasemide period. Kaliuresis was similar during the two treatment periods, despite the striking differences observed in natriuresis. Neither torasemide nor furosemide induced any significant change in serum electrolyte or creatinine concentrations, or in ammonia levels. The results of this study indicate that torasemide is suitable for the treatment of sodium retention in patients with cirrhosis and ascites.


Assuntos
Ascite/tratamento farmacológico , Diuréticos/uso terapêutico , Furosemida/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Sulfonamidas/uso terapêutico , Adulto , Idoso , Peso Corporal/efeitos dos fármacos , Ácido Canrenoico/administração & dosagem , Ácido Canrenoico/farmacologia , Ácido Canrenoico/uso terapêutico , Terapia Combinada , Dieta Hipossódica , Diuréticos/administração & dosagem , Diuréticos/farmacologia , Feminino , Furosemida/administração & dosagem , Furosemida/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Natriurese/efeitos dos fármacos , Potássio/urina , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacologia , Torasemida
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