[Prognostic factors associated with postoperative complications in liver transplant]. / Factores pronósticos de complicaciones postoperatorias en el transplante hepático.

OBJECTIVES: the postoperative evolution of patients submitted to orthotopic liver transplant (OLT) is frequently associated with the appearance of different types of complications such as renal failure, graft rejection, infections, and neurological disorders. These complications are the most significant causes of early morbidity and mortality in patients undergoing OLT. The purpose of the present study was the identification of factors related to the different postoperative complications after OLT. EXPERIMENTAL DESIGN: a prospective study was carried out. PATIENTS: seventy-eight variables were analyzed in 32 consecutive patients undergoing OLT. The factors independently associated with the appearance of postoperative complications were identified using a stepwise logistic regression analysis. RESULTS: the multivariate analysis showed that malondialdehyde and creatinine pretransplant serum levels were associated with the development of renal dysfunction. The pretransplant levels of haemoglobin and the units of platelets administered during surgery were prognostic factors of infections. Acute graft rejection was predicted by ?-glutamyl transpeptidase and total bilirubin serum levels. The pretransplant sodium and glutaredoxin levels in serum were associated with neurological complications. CONCLUSIONS: we propose these markers for the identification of high-risk patients allowing an early surveillance and/or treatment to improve morbidity and survival in patients submitted to OLT.

Factores pronósticos de complicaciones postoperatorias en el trasplante hepático / No disponible

Objetivo: la evolución postoperatoria de los pacientes sometidosa trasplante hepático ortotópico (THO) se encuentra frecuentementeasociada a la aparición de diversas complicaciones talescomo disfunción renal, rechazo agudo, infecciones y complicacionesneurológicas. Estas complicaciones constituyen las causasmás significativas de morbilidad y mortalidad tempranas en pacientesque reciben un THO. El propósito del presente estudio esla identificación de factores relacionados con las distintas complicacionespostoperatorias del THO. Diseño experimental: se llevóa cabo un estudio prospectivo.Pacientes: se analizaron 78 variables en 32 pacientes consecutivossometidos a THO. Utilizando un análisis de regresión logísticase identificaron aquellos factores asociados de forma independientecon la aparición de complicaciones postoperatorias.Resultados: el análisis multivariante demostró que los nivelespretrasplante en suero de malondialdehído y creatinina estabanasociados con el desarrollo de disfunción renal. Los niveles pretrasplantede hemoglobina y las unidades de plaquetas administradasdurante la cirugía fueron factores pronósticos de infecciones.El rechazo agudo fue pronosticado por los niveles séricos de γ-glutamiltranspeptidasa y de bilirrubina total. Los niveles pretrasplantede sodio y glutaredoxina en suero estuvieron asociados concomplicaciones neurológicas.Conclusiones: proponemos estos marcadores para la identificaciónde pacientes de alto riesgo, permitiendo una vigilanciay/o tratamiento anticipados que mejorarán la morbilidad y la supervivenciaen pacientes sometidos a THO

Objectives: the postoperative evolution of patients submittedto orthotopic liver transplant (OLT) is frequently associated withthe appearance of different types of complications such as renalfailure, graft rejection, infections, and neurological disorders.These complications are the most significant causes of early morbidityand mortality in patients undergoing OLT. The purpose ofthe present study was the identification of factors related to thedifferent postoperative complications after OLT. Experimental design:a prospective study was carried out.Patients: seventy-eight variables were analyzed in 32 consecutivepatients undergoing OLT. The factors independently associatedwith the appearance of postoperative complications wereidentified using a stepwise logistic regression analysis.Results: the multivariate analysis showed that malondialdehydeand creatinine pretransplant serum levels were associatedwith the development of renal dysfunction. The pretransplant levelsof haemoglobin and the units of platelets administered duringsurgery were prognostic factors of infections. Acute graft rejectionwas predicted by γ-glutamyl transpeptidase and total bilirubinserum levels. The pretransplant sodium and glutaredoxin levels inserum were associated with neurological complications.Conclusions: we propose these markers for the identificationof high-risk patients allowing an early surveillance and/or treatmentto improve morbidity and survival in patients submitted toOLT

NADPH and oxidized thioredoxin mediate redox interconversion of calf-liver and Escherichia coli thioredoxin reductase.

The activity of pure calf-liver and Escherichia coli thioredoxin reductases decreased drastically in the presence of NADPH or NADH, while NADP+, NAD+ and oxidized E. coli thioredoxin activated both enzymes significantly, particularly the bacterial one. The loss of activity under reducing conditions was time-dependent, thus suggesting an inactivation process: in the presence of 0.24 mM NADPH the half-lives for the E. coli and calf-liver enzymes were 13.5 and 2 min, respectively. Oxidized E. coli thioredoxin fully protected both enzymes from inactivation, and also promoted their complete reactivation after only 30 min incubation at 30 degrees C. Lower but significant protection and reactivation was also observed with NADP+ and NAD+. EDTA protected thioredoxin reductase from NADPH inactivation to a great degree, thus indicating the participation of metals in the process; EGTA did not protect the enzyme from redox inactivation. Thioredoxin reductase was extensively inactivated by NADPH under aerobic and anaerobic conditions, thus excluding the participation of O2 or oxygen active species in redox inactivation. The loss of thioredoxin reductase activity promoted by NADPH was much faster and complete in the presence of NAD+ glycohydrolase, thus suggesting that inactivation was related to full reduction of the redox-active disulfide. Those results indicate that thioredoxin reductase activity can be modulated in bacteria and mammals by the redox status of NADP(H) and thioredoxin pools, in a similar way to glutathione reductase. This would considerably expand the regulatory potential of the thioredoxin-thioredoxin reductase system with the enzyme being self-regulated by its own substrate, a regulatory protein.