Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Liver Transpl ; 22(9): 1186-96, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27114030

RESUMO

In human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients, the accelerated severity of liver disease, associated comorbidities, and mortality on the waiting list could change the possibility and results of liver transplantation (LT). Intention-to-treat survival analysis (ITTA) can accurately estimate the applicability and efficacy of LT. The primary objective of this study was to compare the survival of patients with HCV with and without HIV infection. We analyzed a cohort of 199 patients with HCV infection enrolled for LT between 1998 and 2015; 17 were also infected with HIV. The patients with HCV/HIV coinfection had higher mortality on the waiting list than those with HCV monoinfection (35.3% versus 4.6%; P < 0.001). ITTA at 1, 3, and 4 years was 75%, 64%, and 57% for HCV monoinfection and 52%, 47%, and 39% for HCV/HIV coinfection, respectively (Wilcoxon test P < 0.05). The ITTA at 1, 3, 6, and 12 months was 96%, 91%, 87%, and 75% for HCV monoinfection and 76%, 70%, 64%, and 52% for HCV/HIV coinfection, respectively (log-rank P < 0.05; Wilcoxon test P < 0.01). A Cox regression analysis was carried out including all variables with predictive value in the univariate analysis, showing that only donor age > 70 years (hazard ratio [HR] = 3.12; P < 0.05), United Network for Organ Sharing status 1 (HR = 10.1; P < 0.01), Model for End-Stage Liver Disease (HR = 1.13; P < 0.001), and HIV coinfection (HR = 2.65; P < 0.05) had independent negative predictive value for survival. In conclusion, our study indicates that HIV coinfection is a factor in mortality prior to transplantation and associated with higher mortality on the waiting list. Liver Transplantation 22 1186-1196 2016 AASLD.


Assuntos
Coinfecção/mortalidade , Doença Hepática Terminal/mortalidade , Infecções por HIV/complicações , Hepatite C Crônica/mortalidade , Hepatite C Crônica/cirurgia , Transplante de Fígado , Listas de Espera/mortalidade , Adulto , Fatores Etários , Coinfecção/virologia , Doença Hepática Terminal/cirurgia , Feminino , HIV/isolamento & purificação , Infecções por HIV/virologia , Hepacivirus/isolamento & purificação , Hepatite C Crônica/complicações , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Índice de Gravidade de Doença , Análise de Sobrevida , Transplantes/virologia
2.
Transplantation ; 97(9): 901-7, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24646772

RESUMO

BACKGROUND: Institut Georges Lopez-1 preservation solution (IGL-1) is an emerging extracellular-type electrolyte solution, low in viscosity, containing polyethylene glycol 35 as a colloid. Although IGL-1 has shown beneficial outcomes in kidney and liver preservation, this pilot study is the first to evaluate the efficacy of IGL-1 in pancreas transplantation (PT) compared with the University of Wisconsin solution (UW). METHODS: Sixteen Landrace pigs underwent allogeneic PT with 16 hr of cold ischemia. Grafts were preserved with IGL-1 (n=8) or UW (n=8). No immunosuppression was administered. We analyzed graft function, the acute-phase response, and oxidative stress in the pancreatic graft monitoring membrane fluidity and lipid peroxidation. RESULTS: All eight grafts with IGL-1, but only six with UW, were functioning. Graft failures with UW resulted from graft thrombosis. There were no differences between the two solutions in the number of normoglycemic days (IGL-1: 11.5 ± 6.2 versus UW: 8.5 ± 4.4 days, P=0.1357), nor in lipid peroxidation during 16-hr cold ischemia (P=0.672), or reperfusion (P=0.185), but IGL-1 prevented changes in membrane fluidity after reperfusion when compared with UW (P=0.026). CONCLUSION: IGL-1 offered the same degree of safety and effectiveness as UW in our model of pig PT with 16 hr of cold ischemia.


Assuntos
Soluções para Preservação de Órgãos/química , Preservação de Órgãos/métodos , Transplante de Pâncreas/métodos , Pâncreas/patologia , Adenosina/química , Alopurinol/química , Animais , Coloides/química , Eletrólitos , Feminino , Glutationa/química , Terapia de Imunossupressão , Insulina/química , Isquemia , Rim/patologia , Peroxidação de Lipídeos , Fígado/patologia , Estresse Oxidativo , Projetos Piloto , Polietilenoglicóis/química , Rafinose/química , Suínos , Fatores de Tempo , Viscosidade
3.
J Pineal Res ; 56(3): 225-37, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24571249

RESUMO

Free radicals generated within subcellular compartments damage macromolecules which lead to severe structural changes and functional alterations of cellular organelles. A manifestation of free radical injury to biological membranes is the process of lipid peroxidation, an autooxidative chain reaction in which polyunsaturated fatty acids in the membrane are the substrate. There is considerable evidence that damage to polyunsaturated fatty acids tends to reduce membrane fluidity. However, adequate levels of fluidity are essential for the proper functioning of biological membranes. Thus, there is considerable interest in antioxidant molecules which are able to stabilize membranes because of their protective effects against lipid peroxidation. Melatonin is an indoleamine that modulates a wide variety of endocrine, neural and immune functions. Over the last two decades, intensive research has proven this molecule, as well as its metabolites, to possess substantial antioxidant activity. In addition to their ability to scavenge several reactive oxygen and nitrogen species, melatonin increases the activity of the glutathione redox enzymes, that is, glutathione peroxidase and reductase, as well as other antioxidant enzymes. These beneficial effects of melatonin are more significant because of its small molecular size and its amphipathic behaviour, which facilitates ease of melatonin penetration into every subcellular compartment. In the present work, we review the current information related to the beneficial effects of melatonin in maintaining the fluidity of biological membranes against free radical attack, and further, we discuss its implications for ageing and disease.


Assuntos
Melatonina/fisiologia , Fluidez de Membrana/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Antioxidantes/farmacologia , Radicais Livres/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Humanos , Bicamadas Lipídicas/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Melatonina/metabolismo , Camundongos
4.
J Pineal Res ; 55(1): 65-78, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23551302

RESUMO

Ischemia/reperfusion injury (IRI) associated with liver transplantation plays an important role in the induction of graft injury. Prolonged cold storage remains a risk factor for liver graft outcome, especially when steatosis is present. Steatotic livers exhibit exacerbated endoplasmic reticulum (ER) stress that occurs in response to cold IRI. In addition, a defective liver autophagy correlates well with liver damage. Here, we evaluated the combined effect of melatonin and trimetazidine as additives to IGL-1 solution in the modulation of ER stress and autophagy in steatotic liver grafts through activation of AMPK. Steatotic livers were preserved for 24 hr (4°C) in UW or IGL-1 solutions with or without MEL + TMZ and subjected to 2-hr reperfusion (37°C). We assessed hepatic injury (ALT and AST) and function (bile production). We evaluated ER stress (GRP78, PERK, and CHOP) and autophagy (beclin-1, ATG7, LC3B, and P62). Steatotic livers preserved in IGL-1 + MEL + TMZ showed lower injury and better function as compared to those preserved in IGL-1 alone. IGL-1 + MEL + TMZ induced a significant decrease in GRP78, pPERK, and CHOP activation after reperfusion. This was consistent with a major activation of autophagic parameters (beclin-1, ATG7, and LC3B) and AMPK phosphorylation. The inhibition of AMPK induced an increase in ER stress and a significant reduction in autophagy. These data confirm the close relationship between AMPK activation and ER stress and autophagy after cold IRI. The addition of melatonin and TMZ to IGL-1 solution improved steatotic liver graft preservation through AMPK activation, which reduces ER stress and increases autophagy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Fígado Gorduroso/metabolismo , Melatonina/farmacologia , Trimetazidina/farmacologia , Animais , Autofagia/fisiologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fígado Gorduroso/patologia , Histocitoquímica , Transplante de Fígado , Substâncias Protetoras/farmacologia , Ratos , Ratos Zucker , Traumatismo por Reperfusão/metabolismo
5.
Clin Transplant ; 26(1): 111-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21447142

RESUMO

BACKGROUND: Cirrhosis is associated with structural and functional abnormalities of the heart. We examined the evolution of these abnormalities after liver transplantation (LT). METHODS: Sixty cirrhotic patients, without cardiovascular disease, were included. Clinical data, echocardiography, and aminoterminal pro-brain natriuretic peptide (NT-proBNP) levels were analyzed before and after transplantation. Healthy controls (n = 25) were included for reference. RESULTS: Before transplantation, cirrhotic patients had higher left atrium diameter, left ventricular (LV) mass index, and ejection fraction than controls. After transplantation, LV mass index increased (105 ± 31 vs. 119 ± 35 g/m(2) ; p < 0.05), diastolic cardiac function deteriorated, expressed as a reduction in E/A wave ratio (1.105 ± 0.295 vs. 0.798 ± 0.248; p < 0.001), and NT-proBNP levels decreased significantly in patients compared to pre-transplantation values (1759 ± 1154 vs. 1117 ± 600 pg/mL; p < 0.001), although they were still above levels found in controls (1117 ± 600 vs. 856 ± 123 pg/mL; p < 0.05). NT-proBNP levels above 2000 pg/mL before transplantation were significantly associated with risk for cardiovascular events after procedure (37% vs. 9%, p = 0.008). CONCLUSIONS: In cirrhotic patients, diastolic function and cardiac structure deteriorate after LT. Compared to controls, NT-proBNP levels tend to be higher before and after transplantation. The mechanisms and consequences of these results require further study.


Assuntos
Biomarcadores/sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/diagnóstico , Cirrose Hepática/complicações , Transplante de Fígado/efeitos adversos , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Adulto , Idoso , Ecocardiografia Doppler , Feminino , Seguimentos , Insuficiência Cardíaca/etiologia , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
6.
J Pineal Res ; 51(4): 445-53, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21718360

RESUMO

Oxidative stress is involved in ischemia-reperfusion injury and allograft rejection after transplantation. We studied two well-known antioxidants, melatonin and ascorbic acid (AA), in relation to the survival of a pancreas transplantation model without immunosuppression. Forty-eight Landrace pigs were divided into three groups (n = 16 each; eight donors and eight recipients) that received melatonin, AA, or no antioxidant therapy (controls). Melatonin and AA were administered (10 mg/kg body weight) intravenously to donors and recipients during surgery and on postoperative days 1-7. The molecules were also added (5 mm) to a University of Wisconsin preservation solution during organ cold storage. Melatonin significantly delayed acute rejection and prolonged allograft survival (25.1 ± 7.7 days) compared with the controls (8.1 ± 0.8 days, P = 0.013) and the AA group (9.4 ± 1.6 days, P = 0.049). Melatonin reduced indicators of oxidative stress, malondialdehyde, and 4-hydroxyalkenals, in pancreatic samples collected during procurement, cold ischemia, and reperfusion. Melatonin also reduced serum pig-major acute-phase protein/inter-α-trypsin inhibitor heavy chain 4 (pMAP/ITIH(4)) in the early post-transplantation period. AA only partially reduced oxidative damage 30 min postreperfusion and failed to prevent pMAP/ITIH(4) elevations. These findings suggested that melatonin may be a useful therapeutic tool for organ transplantation.


Assuntos
Antioxidantes/uso terapêutico , Ácido Ascórbico/uso terapêutico , Sobrevivência de Enxerto/efeitos dos fármacos , Melatonina/uso terapêutico , Transplante de Pâncreas/métodos , alfa-Globulinas/metabolismo , Animais , Feminino , Estresse Oxidativo/efeitos dos fármacos , Suínos , Transplante Homólogo
7.
World J Surg ; 35(7): 1598-607, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21487851

RESUMO

BACKGROUND: Celsior solution (CS) is a high-sodium, low-potassium, low-viscosity extracellular solution that has been used for liver graft preservation in recent years, although experience with it is still limited. We performed an open-label randomized active-controlled trial comparing CS with the University of Wisconsin solution (UW) for liver transplantation (LT), with a follow-up period of 5 years. METHODS: Adult transplant recipients (n=102) were prospectively randomized to receive either CS (n=51) or UW (n=51). The two groups were comparable with respect to donor and recipient characteristics. The primary outcome measure was the incidence of postreperfusion syndrome (PRS). Secondary outcome measures included primary nonfunction (PNF) or primary dysfunction (PDF), liver retransplantation, and graft and patient survival. Other secondary outcome measures were days in the intensive care unit (ICU) and the rates of acute rejection, chronic rejection, infectious complications, postoperative reoperations, and vascular and biliary complications. RESULTS: In all, 14 posttransplant variables revealed no significant differences between the groups. There were no cases of PNF or PDF. The incidence of PRS was 5.9% in the CS group and 21.6% in the UW group (P=0.041). After reperfusion, CS revealed greater control of serum potassium (P=0.015), magnesium levels (P=0.005), and plasma glucose (P=0.042) than UW. Respective patient survivals at 3, 12, and 60 months were 95.7, 87.2, and 82.0% for the CS group and 95.7, 83.3, and 66.6% for the UW group (P=0.123). CONCLUSIONS: While retaining the same degree of safety and effectiveness as UW for LT, CS may yield postliver graft reperfusion benefits, as shown in this study by a significant reduction in the incidence of PRS and greater metabolic control.


Assuntos
Transplante de Fígado , Soluções para Preservação de Órgãos , Preservação de Órgãos , Complicações Pós-Operatórias/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Adenosina , Adolescente , Adulto , Idoso , Alopurinol , Dissacarídeos , Eletrólitos , Feminino , Seguimentos , Glutamatos , Glutationa , Histidina , Humanos , Insulina , Masculino , Manitol , Pessoa de Meia-Idade , Estudos Prospectivos , Rafinose , Síndrome , Fatores de Tempo , Adulto Jovem
8.
J Pineal Res ; 50(2): 213-21, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21108657

RESUMO

Chronic organ-donor shortage has required the acceptance of steatotic livers for transplantation purposes despite the higher risk of graft dysfunction or nonfunction associated with the cold ischemia-reperfusion injury. This study evaluated the use of melatonin as an additive to Institute Georges Lopez (IGL-1) solution for protecting nonsteatotic and steatotic liver grafts against cold ischemia-reperfusion injury. In the current investigation, we used an ex vivo isolated perfused rat liver model. Steatotic and nonsteatotic livers were preserved for 24 hr (4°C) in University of Wisconsin or IGL-1 solutions with or without melatonin, as well as in University of Wisconsin solution alone. Thereafter, livers were subjected to 2-hr reperfusion (37°C). We assessed hepatic injury (transaminases) and function [bile production and sulfobromophthalein (BSP) clearance, vascular resistance], as well as other factors potentially implicated in the high vulnerability of steatotic livers against ischemia-reperfusion injury (oxidative stress and related inflammatory mediators including nitric oxide and cytokines). We also evaluated well-known cytoprotective factors as hemeoxygenase 1 (HO-1). Fatty livers preserved in IGL-1 solution enriched with melatonin showed lower transaminase levels and higher bile production and BSP clearance when compared to those obtained for livers maintained in IGL-1 solution alone. A significant diminution of vascular resistance was also observed when melatonin was added to the IGL-1 solution. The melatonin benefits correlated with the generation of nitric oxide (through constitutive e-NOS activation) and the prevention of oxidative stress and inflammatory cytokine release including tumor necrosis factor and adiponectin, respectively. The addition of melatonin to IGL-1 solution improved nonsteatotic and steatotic liver graft preservation, limiting their risk against cold ischemia-reperfusion injury.


Assuntos
Fígado Gorduroso/tratamento farmacológico , Fígado/efeitos dos fármacos , Melatonina/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Animais , Fígado Gorduroso/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Zucker
9.
J Cell Biochem ; 110(5): 1219-25, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20564217

RESUMO

Cholestasis, encountered in a variety of clinical disorders, is characterized by intracellular accumulation of toxic bile acids in the liver. Furthermore, oxidative stress plays an important role in the pathogenesis of bile acids. Taurolithocholic acid (TLC) was revealed in previous studies as the most pro-oxidative bile acid. Melatonin, a well-known antioxidant, is a safe and widely used therapeutic agent. Herein, we investigated the hepatoprotective role of melatonin on lipid and protein oxidation induced by TLC alone and in combination with FeCl(3) and ascorbic acid in rat liver homogenates and hepatic membranes. The lipid peroxidation products, malondialdehyde and 4-hydroxyalkenals (MDA + 4-HDA), and carbonyl levels were quantified as indices of oxidative damage to hepatic lipids and proteins, respectively. In the current study, the rise in MDA + 4-HDA levels induced by TLC was inhibited by melatonin in a concentration-dependent manner in both liver homogenates and in hepatic membranes. Melatonin also had protective effects against structural damage to proteins induced by TLC in membranes. These results suggest that the indoleamine melatonin may potentially act as a protective agent in the therapy of those diseases that involve bile acid toxicity.


Assuntos
Fígado/efeitos dos fármacos , Melatonina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ácido Taurolitocólico/toxicidade , Aldeídos/metabolismo , Animais , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Cloretos/farmacologia , Colagogos e Coleréticos/toxicidade , Relação Dose-Resposta a Droga , Compostos Férricos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Malondialdeído/metabolismo , Oxirredução/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA