Folding and dimerization kinetics of bone morphogenetic protein-2, a member of the transforming growth factor-ß family.

The kinetics of folding and dimerization of bone morphogenetic protein-2 (BMP-2), a disulfide-connected, homodimeric cystine-knot protein and a member of the transforming growth factor-ß superfamily, was analyzed under a variety of different conditions. Refolding and dimerization of BMP-2 were extremely slow under all conditions studied, and could be described by consecutive first-order reactions involving at least one long-lived intermediate. The rate constants vary from ~ 0.2 × 10(-5) to ~ 3.5 × 10(-5) s(-1), and were strongly dependent on temperature, redox conditions, and the presence of stabilizing or destabilizing ions. In particular, the combined impact of ionic strength and redox conditions on the rates indicates that electrostatic interactions control thiol-disulfide exchange reactions on the path from the unfolded and reduced monomers to the disulfide-connected growth factor in a rate-determining way.

Clinical outcomes with off-pump coronary surgery after angioplasty with stent.

INTRODUCTION AND OBJECTIVES: The aim was to determine whether prior coronary stent implantation affects postoperative outcomes in patients undergoing coronary artery bypass grafting. METHODS: Between January 2005 and April 2008, a retrospective analysis was carried out to evaluate the effect of prior coronary stent implantation in patients undergoing off-pump coronary surgery on the incidence of major cardiovascular events in the postoperative period (i.e. at 30 days or during postoperative hospitalization). RESULTS: In total, 796 consecutive patients underwent coronary artery bypass grafting. Of these, 116 (14.6%) had a coronary stent at the time of surgery. Patients with and without stents had similar levels of risk (i.e. EuroSCORE). Multivariate analysis, adjusted for the presence of confounding variables (i.e. preoperative left ventricular ejection fraction <40%, critical preoperative state, age, history of cerebrovascular accident, recent acute myocardial infarction, number of diseased coronary vessels, incomplete revascularization and on-pump conversion), showed that the presence of a stent was significantly associated with increased risks of postoperative myocardial infarction (relative risk [RR]=3.13; 95% confidence interval [CI], 1.75-5.96), in-hospital cardiac mortality (RR=4.62; 95% CI, 1.76-12.11) and in-hospital all-cause mortality (RR=3.65; 95% CI, 1.60-8.34). CONCLUSIONS: In our experience, coronary artery stent implantation prior to coronary surgery was associated with increased risks of postoperative myocardial infarction, cardiac mortality and all-cause mortality in the postoperative period.

Resultados de la cirugía coronaria sin circulación extracopórea tras angioplastia con stent / Clinical outcomes with off-pump coronary surgery after angioplasty with stent

Introducción y objetivos. Evaluar el impacto de la implantación de stents coronarios previa a la cirugía de revascularización miocárdica en los resultados postoperatorios de ésta. Métodos. Desde enero de 2005 hasta abril de 2008, se evaluó retrospectivamente el impacto de la implantación de stents coronarios previa a la cirugía coronaria sin circulación extracorpórea en la incidencia de eventos cardiovasculares mayores en el postoperatorio (30 días o ingreso hospitalario postoperatorios). Resultados. Se sometió a 796 pacientes consecutivos a revascularización miocárdica quirúrgica; 116 (14,6%) portaban algún stent coronario en el momento de la cirugía. Los grupos con stent y sin stent tenían un perfil de riesgo similar (EuroSCORE). En el análisis multivariable, ajustando el riesgo por las variables de confusión detectadas (fracción de eyección del ventrículo izquierdo preoperatoria < 40%, estado crítico preoperatorio, edad, antecedentes de accidente cerebrovascular agudo, infarto miocárdico agudo previo reciente, número de vasos coronarios enfermos, revascularización quirúrgica incompleta y conversión a circulación extracorpórea) se detectó que el ser portador de stent se asociaba de forma significativa a un mayor riesgo de infarto miocárdico postoperatorio (RR = 3,13; intervalo de confianza [IC] del 95%, 1,75-5,96), mortalidad cardiaca hospitalaria (RR = 4,62; IC del 95%, 1,76-12,11) y mortalidad hospitalaria por todas las causas (RR = 3,65; IC del 95%, 1,6-8,34). Conclusiones. En nuestra experiencia, la implantación previa de stents coronarios se asocia a un mayor riesgo de infarto miocárdico y mortalidad cardiaca y por todas las causas en el postoperatorio de la cirugía coronaria (AU)

Introduction and Objectives. The aim was to determine whether prior coronary stent implantation affects postoperative outcomes in patients undergoing coronary artery bypass grafting. Methods. Between January 2005 and April 2008, a retrospective analysis was carried out to evaluate the effect of prior coronary stent implantation in patients undergoing off-pump coronary surgery on the incidence of major cardiovascular events in the postoperative period (ie, at 30 days or during postoperative hospitalization). Results. In total, 796 consecutive patients underwent coronary artery bypass grafting. Of these, 116 (14.6%) had a coronary stent at the time of surgery. Patients with and without stents had similar levels of risk (ie, EuroSCORE). Multivariate analysis, adjusted for the presence of confounding variables (ie, preoperative left ventricular ejection fraction <40 critical preoperative state age history of cerebrovascular accident recent acute myocardial infarction number diseased coronary vessels incomplete revascularization and on-pump conversion showed that the presence a stent was significantly associated with increased risks postoperative relative risk rr="3.65;" 95 confidence interval ci 1 75-5 96 in-hospital cardiac mortality 76-12 11 all-cause 60-8 34 conclusions in our experience artery implantation prior to surgery period inhospital (AU)