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1.
J Hepatol ; 65(1): 57-65, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26988732

RESUMO

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF. METHODS: We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF. RESULTS: Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)µg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001). CONCLUSIONS: NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome. LAY SUMMARY: Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.


Assuntos
Insuficiência Hepática Crônica Agudizada , Injúria Renal Aguda , Biomarcadores , Humanos , Lipocalina-2 , Cirrose Hepática , Prognóstico
2.
Langenbecks Arch Surg ; 400(8): 979-83, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26566989

RESUMO

INTRODUCTION: Ascites is a common complication of liver cirrhosis and represents the main cause of hospitalization among patients with cirrhosis. First-line therapy for those patients is the use of diuretics and dietary sodium restriction. However, 10 % of patients per year become therapy refractory to diuretic treatment with the need of repeated high-volume paracentesis or transjugular intrahepatic portosystemic shunt (TIPS). For these patients, an automated pump system (Alfapump/Sequana Medical) was developed. Here, we describe our single-center experience of ten consecutively implanted pump systems. PATIENTS AND METHODS: Between 08/13 and 11/14, ten Alfapump systems were implanted in patients with refractory ascites all suffering from liver cirrhosis. Those patients were treated as a bridge to transplant (4/10) or as an end-stage therapy (6/10). Median follow-up was 165 days (23-379 days). RESULTS: Postimplant, the need of paracentesis could be markedly reduced to a mean of 0.45 (0-4/month) per month. In eight patients, paracentesis was not needed after implantation of the pump system. The median daily output volume was 1000 ml/day (450-2000 ml/day). Prerenal insufficiency was a recurrent complication in the postoperative period. DISCUSSION: The Alfapump system is a useful system in the treatment of patients suffering from therapy refractory ascites. However, due to the high level of comorbidities, careful patient selection and postoperative monitoring are required.


Assuntos
Ascite/etiologia , Ascite/terapia , Cirrose Hepática/complicações , Próteses e Implantes , Feminino , Humanos , Testes de Função Renal , Tempo de Internação/estatística & dados numéricos , Testes de Função Hepática , Masculino , Duração da Cirurgia , Paracentese , Seleção de Pacientes , Derivação Portossistêmica Transjugular Intra-Hepática , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
3.
Chirurg ; 84(5): 385-90, 2013 May.
Artigo em Alemão | MEDLINE | ID: mdl-23519379

RESUMO

Liver transplantation is the optimal therapy for patients with non-resectable early stage hepatocellular carcinoma (HCC) which is limited to the liver. During the sometimes long waiting period patients usually receive neoadjuvant bridging therapy to avoid tumor progression. The armamentarium of bridging therapies includes local ablative and systemic therapies as well as liver resection. The oncological benefit of neoadjuvant therapy for patients who receive a liver transplantation is unclear; however, bridging therapy keeps patients eligible for transplantation in the formal framework of current allocation rules. Moreover, response to therapy may serve as a surrogate marker for favorable tumor biology and may therefore help to guide the selection process for patients undergoing liver transplantation for HCC.


Assuntos
Carcinoma Hepatocelular/terapia , Doença Hepática Terminal/terapia , Neoplasias Hepáticas/terapia , Transplante de Fígado , Cadáver , Progressão da Doença , Doença Hepática Terminal/etiologia , Humanos , Terapia Neoadjuvante , Prognóstico , Doadores de Tecidos/provisão & distribuição , Listas de Espera
5.
Clin Nephrol ; 74(6): 474-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21084052

RESUMO

Kidney disease is a rare complication of Campylobacter jejuni (C. jejuni) enteritis. We here present the case of an 18-year-old male patient with crampy abdominal pain, vomiting, diarrhea, and fever. Three weeks later urinalysis revealed mild proteinuria and hematuria and a marked raise in serum creatinine was observed. Renal biopsy demonstrated acute endocapillary glomerulonephritis with mesangial IgM (immunoglobuline M) deposits. Extensive workup revealed no signs of skin or joint disease, thus excluding Henoch-Schönlein purpura. Due to persistent abdominal discomfort further gastro-enterological tests were performed and eventually Campylobacter jejuni was isolated from the patient's feces. In the absence of other precipitating factors for renal diseases we presumed an association between the bacterial infection and this postinfectious glomerulonephritis. Over a time period of 6 months the patient's kidney function normalized completely. However, long-term prognosis remains unclear. In addition to the case report, we conducted a review of the literature with results underlining Campylobacter jejuni's potential to trigger various types of immune mediated kidney diseases.


Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter jejuni/patogenicidade , Enterite/microbiologia , Mesângio Glomerular/imunologia , Glomerulonefrite/etiologia , Adolescente , Biópsia , Infecções por Campylobacter/complicações , Infecções por Campylobacter/imunologia , Campylobacter jejuni/imunologia , Diagnóstico Diferencial , Enterite/complicações , Enterite/imunologia , Fezes/microbiologia , Mesângio Glomerular/patologia , Glomerulonefrite/imunologia , Glomerulonefrite/patologia , Humanos , Imunoglobulina M/análise , Masculino , Valor Preditivo dos Testes
6.
Gut ; 58(5): 688-98, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19106147

RESUMO

BACKGROUND: cJun terminal kinase (JNK) is constitutively activated in most hepatocellular carcinomas (HCCs), yet its exact role in carcinogenesis remains controversial. While tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is known as a major mediator of acquired immune tumour surveillance, and is currently being tested in clinical trials as a novel cancer therapy, the resistance of many tumours to TRAIL and concerns about its toxicity in vivo represent obstacles to its clinical application. In this study we investigated whether JNK activity in HCC could contribute to the resistance to apoptosis in these tumours. METHODS: The effect of JNK/Jun inhibition on receptor-mediated apoptosis was analysed by pharmacological inhibition or RNA interference in cancer cells and non-tumour cells isolated from human liver or transgenic mice lacking a phosphorylation site for Jun. RESULTS: JNK inhibition caused cell cycle arrest, enhanced caspase recruitment, and greatly sensitised HCC cells but not normal hepatocytes to TRAIL. TRAIL-induced activation of JNK could be effectively interrupted by administration of the JNK inhibitor SP600125. CONCLUSIONS: Expression and TRAIL-dependent feedback activation of JNK likely represent a mechanism by which cancer cells escape TRAIL-mediated tumour surveillance. JNK inhibition might represent a novel strategy for specifically sensitising HCC cells to TRAIL thus opening promising therapeutic perspectives for safe and effective use of TRAIL in cancer treatment.


Assuntos
Apoptose/genética , Carcinoma Hepatocelular/tratamento farmacológico , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias Hepáticas/tratamento farmacológico , Animais , Antracenos/uso terapêutico , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Western Blotting , Carcinoma Hepatocelular/genética , Caspases/metabolismo , Ciclo Celular/genética , Linhagem Celular Tumoral , Ativação Enzimática , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Neoplasias Hepáticas/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico , Receptor fas/metabolismo
7.
Digestion ; 73(2-3): 167-70, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16837801

RESUMO

A 24-year-old female patient presented to her community hospital with mild elevations of serum transaminase and bilirubin levels. Because of multiple sclerosis, she was treated with interferon beta-1a for 6 weeks. After exclusion of viral hepatitis due to hepatitis A-E, interferon beta-1a was withdrawn under the suspicion of drug-induced hepatitis. One week later, she was admitted again to her community hospital with severe icterus. The transaminase and bilirubin levels were highly elevated, and a beginning impairment of the liver synthesis was expressed by a reduced prothrombin time. The confinement to our department occurred with a fulminant hepatitis and the suspicion of beginning acute liver failure. There was no evidence for hepatitis due to potentially hepatotoxic viruses, alcoholic hepatitis, Budd-Chiari syndrome, hemochromatosis, and Wilson's disease. In her serum there were high titers of liver-kidney microsomal type 1 autoantibody; the serum gamma globulin levels were in the normal range. Fine-needle aspiration biopsy of the liver ruled out an autoimmune hepatitis but showed signs of drug-induced toxicity. During the interview, she admitted that for 'general immune system stimulation' she had been drinking Noni juice, a Polynesian herbal remedy made from a tropical fruit (Morinda citrifolia), during the past 4 weeks. After cessation of the Noni juice ingestion, her transaminase levels normalized quickly and were in the normal range within 1 month.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Morinda/toxicidade , Fitoterapia/efeitos adversos , Adulto , Feminino , Humanos , Testes de Função Hepática
8.
Eur J Surg Oncol ; 31(9): 994-9, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16076546

RESUMO

AIMS: Recently, there is a tendency to expand tumour sizes qualifying for OLT. The present study re-evaluates tumour size and histopathological features as selection criteria for OLT. METHODS: Retrospective analysis of 93 adult HCC patients underwent OLT between June 1985 and December 2003. Median follow-up was 28 months (1-222 months). The Milan criteria were routinely applied since 1994. RESULTS: Five year survival rate of HCC patients was significantly lower than in patients transplanted for benign diseases, 41 and 71%, respectively (p<0.0001). Multivariate analysis revealed that the presence of vascular invasion represents the most significant predictor (p<0.001) affecting the survival rate. Survival was also significantly impaired when the tumour size was >5 cm (p<0.05), whereas the number of nodules had no significant effect on survival. Consequently, the survival rate for HCC fulfilling the Milan criteria histologically improved to 70% since 1994. CONCLUSION: Tumour size has been shown to be the most important pre-operatively detectable predictor for patient survival after OLT.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Adolescente , Adulto , Idoso , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Taxa de Sobrevida
10.
Internist (Berl) ; 44(6): 740-5, 2003 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-14567110

RESUMO

We report the case of a 52-years-old male patient, who was diagnosed with subcutaneous alveolar echinococcosis 6 months after liver transplantation for HCV-related cirrhosis. Nether the explanted nor the transplantated liver revealed an echinococcus focus. Therefore a rare primary extrahepatic manifestation was likely. Interestingly, the echinococcal larvae had developed protoscolices. The development of mature tapeworms in human is a rarity, which could be related to the immunosuppressive therapy after liver transplantation. The patient was curatively treated by surgical removal of the subcutaneous tumor and a postoperative therapy with albendazole. Furthermore, HCV reinfection (genotype 2b) was successfully treated with interferone alpha 2b and ribavirine for 6 months.


Assuntos
Neoplasias da Mama Masculina/diagnóstico , Carcinoma Hepatocelular/cirurgia , Equinococose/diagnóstico , Doença da Mama Fibrocística/diagnóstico , Encefalopatia Hepática/cirurgia , Terapia de Imunossupressão , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Complicações Pós-Operatórias/diagnóstico , Tela Subcutânea , Biópsia , Mama/patologia , Neoplasias da Mama Masculina/patologia , Diagnóstico Diferencial , Equinococose/patologia , Doença da Mama Fibrocística/patologia , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/patologia , Humanos , Fígado/patologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Masculino , Complicações Pós-Operatórias/patologia , Recidiva , Tela Subcutânea/patologia
11.
Br J Pharmacol ; 139(1): 81-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12746226

RESUMO

1. Cirrhosis is associated with cardiovascular and renal dysfunction including sodium retention. Many vasoactive peptides such as atrial natriuretic peptide (ANP) and endothelin-1 (ET-1) are degraded by neutral endopeptidase 24.11 (NEP). We investigated the hemodynamic and renal effects of thiorphan, a NEP inhibitor, in a rat cirrhosis model. 2. Cirrhosis was induced by chronic bile duct ligation, and controls had sham operation. Systemic and renal hemodynamics in conscious, restrained animals were determined using radiolabeled microspheres, and glomerular filtration rate (GFR) was measured by (3)H-inulin clearance. Plasma ANP and ET-1, and renal cGMP and Na(+) - K(+) ATPase activity were assayed. These variables were measured at baseline and after intravenous infusion of thiorphan (0.5 mg kg(-1) loading dose followed by 0.1 mg kg(-1) min(-1) x 30 min). 3. Thiorphan significantly decreased cardiac output, and increased systemic vascular resistance in controls, whereas in cirrhotic rats these variables were unchanged. 4. Compared to the controls, cirrhotic rats showed a decreased baseline GFR and urine sodium excretion, and the latter was significantly increased by thiorphan. 5. Thiorphan increased plasma ET-1 levels in controls, but not cirrhotic rats. ANP levels were not significantly increased in either group by thiorphan. 6. Thiorphan significantly increased cGMP concentrations and decreased Na(+) - K(+) ATPase activity of renal medulla but not cortex in cirrhotic rats; no effect was observed in the control rats. 7. We conclude that thiorphan induces natriuresis in cirrhotic rats by a direct renal medullary mechanism via cGMP and Na(+) - K(+) ATPase, without affecting systemic hemodynamics. This may potentially be useful in patients with ascites.


Assuntos
Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Rim/efeitos dos fármacos , Cirrose Hepática Experimental/fisiopatologia , Neprilisina/antagonistas & inibidores , Tiorfano/farmacologia , Animais , Fator Natriurético Atrial/sangue , GMP Cíclico/metabolismo , Endotelina-1/sangue , Taxa de Filtração Glomerular/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Rim/metabolismo , Rim/fisiopatologia , Cirrose Hepática Experimental/sangue , Cirrose Hepática Experimental/metabolismo , Natriurese/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Sódio/urina , ATPase Trocadora de Sódio-Potássio/metabolismo
13.
Gut ; 50(1): 106-10, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11772976

RESUMO

BACKGROUND AND AIMS: Diagnosis of moderately impaired renal function is of particular importance in patients with cirrhosis of the liver. Whereas patients with a markedly impaired glomerular filtration rate can be diagnosed easily by elevated serum creatinine concentrations, moderately reduced renal function may be missed by this conventional parameter. Recently, cystatin C has been suggested as a sensitive marker of renal function, independent of sex or muscle mass. Therefore, the aim of this study was to investigate the value of serum cystatin C concentration for the detection of moderately impaired renal function. METHODS: Ninety seven in-hospital patients with cirrhosis and a 24 hour creatinine clearance of at least 40 ml/min were investigated and divided into group 1 (creatinine clearance > or = 70 ml/min; n = 55) and group 2 (creatinine clearance 40-69 ml/min; n = 42). RESULTS: Serum cystatin C concentrations (mean (SD): 1.31 (0.51) v 1.04 (0.34) mg/l (p = 0.008)) and creatinine concentrations (1.03 (0.52) v 0.86 (0.22) mg/100 ml (p=0.03)) were higher in group 2 than in group 1; there was no significant difference in urea concentrations. Receiver-operator characteristics (ROC) revealed a differential diagnostic advantage of cystatin C over creatinine and urea. At cut off concentrations of 1.0 mg/l, 0.9 mg/100 ml, and 28 mg/100 ml, respectively, cystatin C, creatinine, and urea exhibited 69%, 45%, and 44% sensitivity (p<0.05). As patients with a small muscle mass or reduced physical activity could be particularly prone to overestimation of their renal function, separate analyses were performed for the subgroups of female and Child-Pugh class C patients, respectively. In both groups, discrimination between patients with moderately impaired and normal renal function was best with cystatin C. In female patients, sensitivity of cystatin C (77.8%) was superior (p<0.05) to that of creatinine (38.9%) and urea (41.2%). In Child-Pugh C patients, the ROC curve was significantly better for cystatin C than for creatinine. CONCLUSIONS: Serum cystatin C determination could be a valuable tool in patients with cirrhosis, particularly with Child-Pugh class C or in female patients, for early diagnosis of moderately impaired renal function.


Assuntos
Cistatinas/sangue , Rim/metabolismo , Cirrose Hepática/metabolismo , Biomarcadores/sangue , Creatinina/sangue , Cistatina C , Feminino , Humanos , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade , Fatores Sexuais , Estatísticas não Paramétricas , Ureia/sangue
14.
Transplantation ; 72(10): 1692-9, 2001 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-11726835

RESUMO

BACKGROUND: Microcirculatory failure, activation of Kupffer cells (KC), and the formation of reactive oxygen species (ROS) are considered pivotal mechanisms of reperfusion injury after orthotopic liver transplantation. However, the sequence of these events and their impact on early graft function remain controversial. We therefore investigated whether KC induce microcirculatory disturbances through ROS release and whether microcirculatory failure contributes to early graft function after liver transplantation. METHODS: Donor livers of Lewis rats were pretreated either with saline or with gadolinium chloride (GdCl3), an inhibitor of KC function (n=8 each). Syngeneic OLT was performed after 24 hr of hypothermic preservation in University of Wisconsin solution. RESULTS: Intravital microscopy revealed significantly higher sinusoidal perfusion rates in GdCl3-treated allografts (92+/-1.1% vs. 75.7+/-0.8%; P<0.001) compared with untreated controls; permanent leukocyte sticking in sinusoids (23.5+/-2.1 vs. 62.6+/-3.3 cells/lobule, P<0.001) and in postsinusoidal venules (153.1+/-10.4 vs. 446.6+/-46.4 cells/mm(2), P<0.001) were markedly attenuated in GdCl3-treated allografts. Improvement of microcirculatory parameters in GdCl3-treated livers was correlated with a significant reduction of plasma glutathione disulfide formation by KC-derived ROS (0.96+/-0.1 microM vs. 1.79+/-0.5 microM; P<0.01). Despite these beneficial effects, GdCl3-pretreatment failed to improve postischemic alanine aminotransferase release and bile flow. CONCLUSIONS: Microcirculatory failure after liver transplantation is related to KC-derived oxidant stress but not involved in early graft dysfunction.


Assuntos
Células de Kupffer/fisiologia , Circulação Hepática , Transplante de Fígado/efeitos adversos , Estresse Oxidativo , Traumatismo por Reperfusão/etiologia , Animais , Gadolínio/farmacologia , Glutationa/sangue , Dissulfeto de Glutationa/sangue , Fígado/patologia , Fígado/ultraestrutura , Circulação Hepática/efeitos dos fármacos , Masculino , Microcirculação/efeitos dos fármacos , Ratos , Ratos Endogâmicos Lew , Transplante Homólogo
15.
Chirurg ; 71(7): 808-19, 2000 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-10986603

RESUMO

INTRODUCTION: Liver transplantation is the method of choice for metabolic diseases and end-stage liver failure. METHODS: At the Klinikum Grosshadern we have performed liver transplantation for inborn errors of metabolism in 24 patients (5.3% of all transplantations, 16 adults, age 39 +/- 13 years; 8 children, age 9 +/- 3 years); 19 patients received a transplant for end-stage liver disease, and in 5 cases because of fulminant hepatic failure. RESULTS: Twenty-four patients received 27 transplants. In 3 cases, a split-liver transplantation was performed; one patient received a combined lung-liver graft. The 5-year survival rate for children is 100% and for adults 68%. CONCLUSIONS: Liver transplantation for inborn errors of metabolism not only replaces the diseased organ, but also leads to complete reversal of the metabolic defect.


Assuntos
Terapia Genética , Hepatopatias/cirurgia , Transplante de Fígado , Erros Inatos do Metabolismo/cirurgia , Adulto , Criança , Síndrome de Crigler-Najjar/diagnóstico , Síndrome de Crigler-Najjar/genética , Síndrome de Crigler-Najjar/cirurgia , Doença de Depósito de Glicogênio/diagnóstico , Doença de Depósito de Glicogênio/cirurgia , Hemocromatose/diagnóstico , Hemocromatose/genética , Hemocromatose/cirurgia , Hemofilia A/diagnóstico , Hemofilia A/cirurgia , Degeneração Hepatolenticular/diagnóstico , Degeneração Hepatolenticular/genética , Degeneração Hepatolenticular/cirurgia , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/cirurgia , Hiperoxalúria/diagnóstico , Hiperoxalúria/cirurgia , Recém-Nascido , Hepatopatias/diagnóstico , Hepatopatias/genética , Transplante de Fígado/métodos , Transplante de Fígado/mortalidade , Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/genética , Pessoa de Meia-Idade , Fatores de Tempo , Transplante Homólogo , Tirosinemias/diagnóstico , Tirosinemias/cirurgia , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/genética , Deficiência de alfa 1-Antitripsina/cirurgia
16.
J Hepatol ; 33(2): 236-46, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10952241

RESUMO

BACKGROUND/AIMS: The cardiovascular hormone Atrial Natriuretic Peptide (ANP) attenuates activation of the pro-inflammatory transcription factor NF-kappaB in macrophages. ANP was also shown to protect from ischemia-reperfusion injury of the rat liver. This study aimed to investigate the effects of this immunomodulatory hormone and its second messenger cGMP on the activation of the two redox-sensitive transcription factors AP-1 and NF-kappaB and the expression of corresponding pro-inflammatory target genes during ischemia and reperfusion of the liver. The identification of the mechanisms underlying the protection by ANP should reveal new aspects concerning the pathomechanisms of ischemia/reperfusion injury. METHODS: Rat livers were perfused with and without ANP or 8-Br-cGMP preceding 24 h of cold storage in University of Wisconsin solution. During reperfusion NF-kappaB and AP-1 DNA binding activities were determined in freeze-clamped liver samples by electrophoretic mobility shift assay. Protein levels of p50, p65, and of IkappaB were determined by Western blot. mRNA coding for inducible nitric oxide synthase, cyclooxygenase-2, and TNF-alpha was determined by RT-PCR and Northern blot. RESULTS: After 45 min of reperfusion DNA binding activities of NF-kappaB were increased, whereas in ANP pre-treated livers this effect was markedly reduced. AP-1, another important redox-sensitive transcription factor, was activated and in the course of reperfusion the subunit composition of AP-1 changed as assessed by supershift assays. ANP markedly reduced binding activities of both forms of AP-1. 8-Br-cGMP mimicked the effects of ANP on NF-kappaB and AP-1. Neither inducible nitric oxide synthase nor cyclooxygenase-2 mRNA could be detected. In contrast, a profound expression of transcripts coding for TNF-alpha was detected in the course of reperfusion and ANP markedly reduced TNF-alpha mRNA expression. CONCLUSION: ANP seems to mediate its protective effect during ischemia and reperfusion by reducing the activation of NF-kappaB and AP-1 via cGMP. The reduced binding activity of these redox-sensitive transcription factors was accompanied by a diminished mRNA expression of TNF-alpha, a cytokine known to be involved in cellular damage in ischemia reperfusion injury.


Assuntos
Fator Natriurético Atrial/administração & dosagem , Isquemia/metabolismo , Fígado/irrigação sanguínea , Fígado/metabolismo , NF-kappa B/metabolismo , Fator de Transcrição AP-1/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Animais , Regulação para Baixo/efeitos dos fármacos , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Reperfusão , Traumatismo por Reperfusão/metabolismo
19.
Gastroenterology ; 117(1): 200-10, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10381928

RESUMO

BACKGROUND & AIMS: The extracellular generation of reactive oxygen species (ROS) by Kupffer cells contributes to reperfusion injury of the liver allograft. The endogenous antioxidant glutathione (GSH) can detoxify these ROS; however, this effect might be limited by the low extracellular concentration of GSH. We therefore investigated whether an increase of extracellular GSH protects the liver against reperfusion injury after cold preservation. METHODS: Livers of male Sprague-Dawley rats subjected to 24 hours of cold ischemia in University of Wisconsin solution (4 degrees C) were reperfused for 2 hours in the absence (controls) or presence of 0.5, 1, 2, or 4 mmol/L GSH (n = 4-6 each). RESULTS: Two hours after starting reperfusion of control livers, the sinusoidal release of lactate dehydrogenase and purine nucleoside phosphorylase increased to 247 +/- 96 and 27 +/- 13 mU. min(-1). g liver(-1), respectively, but only to 76 +/- 43 and 10 +/- 4 mU. min(-1). g liver(-1) in the presence of 4 mmol/L GSH. This cytoprotective effect was confirmed histologically by a marked reduction of trypan blue staining of hepatocytes. Compared with control livers, postischemic bile flow was significantly enhanced by GSH (0.15 +/- 0.02 vs. 0.41 +/- 0.11 microL. min(-1). g liver(-1)), indicating improved liver function. During reperfusion of control livers, intracellular GSH content declined from 4.5 +/- 0.3 to 2.3 +/- 0.1 micromol/g liver, but only to 3.8 +/- 0.4 micromol/g liver in the presence of 4 mmol/L GSH. Reperfusion of untreated livers was accompanied by a prolonged increase of portal pressure to maximally 12.5 +/- 1.9 cm H2O, which was significantly attenuated by 4 mmol/L GSH (7.2 +/- 1.4 cm H2O). Similar cytoprotective and hemodynamic effects were observed with 2 mmol/L GSH, but not with 0.5 and 1 mmol/L GSH. CONCLUSIONS: Treatment of cold-preserved livers with GSH upon reperfusion prevents damage of hepatocytes, deterioration of the hepatic circulation, and loss of intracellular GSH. In view of these protective effects and its low toxicity in humans, GSH should be considered a candidate drug for prevention of ROS-related reperfusion injury of the liver allograft.


Assuntos
Criopreservação , Glutationa/farmacologia , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , Traumatismo por Reperfusão/prevenção & controle , Animais , Glutationa/metabolismo , Técnicas In Vitro , Membranas Intracelulares/metabolismo , Isquemia/fisiopatologia , L-Lactato Desidrogenase/metabolismo , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Circulação Hepática/efeitos dos fármacos , Masculino , Sistema Porta/fisiopatologia , Pressão , Purina-Núcleosídeo Fosforilase/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
20.
Hepatology ; 28(5): 1309-17, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9794916

RESUMO

The aim of our studies was to investigate hormonal prevention of hepatic preservation damage by the atrial natriuretic peptide (ANP) and the mechanisms involved. Isolated perfusion of rat livers was performed in a nonrecirculating fashion. Twenty minutes of preischemic perfusion was performed with or without different concentrations of ANP, followed by 24-hour storage in cold University of Wisconsin (UW) solution. Two hundred nanomoles of ANP prevented hepatocellular damage during a 2-hour reperfusion period as indicated by a marked attenuation of the sinusoidal efflux of lactate dehydrogenase (LDH) and purine nucleoside phosphorylase (PNP), and by reduced Trypan blue uptake. Furthermore, postischemic bile flow as an indicator of liver function was significantly improved by about 60% with 200 nmol/L ANP. No protection was conveyed by 20 nmol/L ANP nor by pretreatment with 200 nmol/L ANP for only 10 minutes. The effects of ANP seemed to be mediated by the guanylate cyclase-coupled A (GC-A) receptor and cyclic guanosine monophosphate (cGMP): whereas expression of both GC-A and GC-B receptors as well as of the GC-C receptor was found, cGMP did protect from ischemia-reperfusion damage, but selective ligands of the B and C receptor did not. To begin to determine the mechanisms of ANP-mediated protection, different parameters were investigated: ANP had no effect on portal pressure as an indicator of hepatic circulation, nor on intracellular energy depletion determined by adenosine nucleotide concentration. However, the marked augmentation of nuclear factor kappaB (NF-kappaB) binding activity during reperfusion was prevented in ANP-pretreated livers. In conclusion, pretreatment with ANP protects the rat liver from cold ischemia-reperfusion damage. This effect is mediated via the GC-A receptor and cGMP, and may be linked to an influence of ANP on NF-kappaB activation. Thus, ANP signaling via the GC-A receptor should be considered as a new pharmacological target to prevent preservation injury of the liver.


Assuntos
Temperatura Baixa , Guanilato Ciclase/metabolismo , Isquemia , Fígado/irrigação sanguínea , Receptores do Fator Natriurético Atrial/fisiologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Fator Natriurético Atrial/uso terapêutico , GMP Cíclico/análogos & derivados , GMP Cíclico/fisiologia , GMP Cíclico/uso terapêutico , L-Lactato Desidrogenase/metabolismo , Masculino , NF-kappa B/metabolismo , Purina-Núcleosídeo Fosforilase/metabolismo , Ratos , Ratos Sprague-Dawley
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