Beta-adrenergic receptor-stimulated apoptosis in cardiac myocytes is mediated by reactive oxygen species/c-Jun NH2-terminal kinase-dependent activation of the mitochondrial pathway

Stimulation of beta-adrenergic receptors (betaARs) causes apoptosis in adult rat ventricular myocytes (ARVMs). The role of reactive oxygen species (ROS) in mediating betaAR-stimulated apoptosis is not known. Stimulation of betaARs with norepinephrine (10 micromol/L) in the presence of prazosin (100 nmol/L) for 24 hours increased the number of apoptotic myocytes as determined by TUNEL staining by 3.6- fold. The superoxide dismutase/catalase mimetics Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP; 10 micromol/L) and Euk-134 decreased betaAR-stimulated apoptosis by 89+/-6% and 76+/-10%, respectively. Infection with an adenovirus expressing catalase decreased betaAR-stimulated apoptosis by 82+/-15%. The mitochondrial permeability transition pore inhibitor bongkrekic acid (50 micromol/L) decreased betaAR-stimulated apoptosis by 76+/-8%, and the caspase inhibitor zVAD-fmk (25 micromol/L) decreased betaAR-stimulated apoptosis by 62+/-11%. betaAR-stimulated cytochrome c release was inhibited by MnTMPyP. betaAR stimulation caused c-Jun NH2-terminal kinase (JNK) activation, which was abolished by MnTMPyP. Transfection with an adenovirus expressing dominant-negative JNK inhibited betaAR-stimulated apoptosis by 81+/-12%, and the JNK inhibitor SP600125 inhibited both betaAR-stimulated apoptosis and cytochrome c release. Thus, betaAR-stimulated apoptosis in ARVMs involves ROS/JNK-dependent activation of the mitochondrial death pathway.     

Stent thrombosis following bare-metal stent implantation: success of emergency percutaneous coronary intervention and predictors of adverse outcome.

AIMS: To investigate the efficacy and outcome of emergency percutaneous coronary interventions (PCI) in patients with stent thrombosis. METHODS AND RESULTS: Between 1995 and 2003, 6058 patients underwent bare-metal stent implantation, of which 95 (1.6%) patients suffered from stent thrombosis. The timing of stent thrombosis was acute in 10 (11%), subacute in 61 (64%), and late in 24 (25%) patients. Procedural and clinical outcomes of emergency PCI for treatment of stent thrombosis were investigated. Emergency PCI was successful in 86 (91%), complicated by death in 2 (2%), and coronary artery bypass grafting in 2 (2%) patients. Myocardial infarction occurred in 77 (81%) patients with a peak creatine kinase level of 1466+/-1570 U/L. Left ventricular ejection fraction declined from 0.54+/-0.19 prior to 0.48+/-0.16 (P<0.05) at the time of stent thrombosis after emergency PCI. A 6 month major adverse clinical events comprised death (11%), reinfarction (16%), and recurrent stent thrombosis (12%) after emergency PCI. Multivariable logistic regression analysis identified the achievement of TIMI 3 flow (OR=0.1, CI 95% 0.01-0.54, P<0.001) and diameter stenosis <50% (OR=0.06, CI 95% 0.01-0.32, P<0.001) during emergency PCI to be independently associated with a reduced risk of cardiac death. Recurrent stent thrombosis was independently predicted by the omission of abciximab (OR=4.3, CI 95% 1.1-17.5). CONCLUSION: Emergency PCI for treatment of stent thrombosis effectively restores vessel patency and flow. Patients presenting with stent thrombosis are at risk for recurrent myocardial infarction and recurrent stent thrombosis.     

The −2518 A/G polymorphism in the monocyte chemoattractant protein 1 gene (MCP-1) is associated with an increased risk of rheumatoid arthritis in Argentine patients

Clinical Rheumatology - The aim of this study was to analyze the influence of nucleotide transition (G/A) in position −2518 of the MCP-1 gene related to the susceptibility of developing RA....     

False positive reactions in confirmatory tests for syphilis in presence of antiphospholipid antibodies: misdiagnosis with prognostic and social consequences

False-positive reactions in the Venereal Disease Research Laboratory test are well known, whereas a positive fluorescent treponemal antibody absorption assay is rarely thought to be a false positive. The non-recognition of serological false-positive tests for syphilis may have negative prognostic and social implications.     

Two-year clinical outcome after implantation of sirolimus-eluting and paclitaxel-eluting stents in diabetic patients.

AIMS: Percutaneous coronary intervention (PCI) in diabetic patients is associated with an increased risk of restenosis and major adverse cardiac events (MACE). We assessed the impact of diabetes on long-term outcome after PCI with sirolimus-eluting (SES) and paclitaxel-eluting (PES) stents. METHODS AND RESULTS: In the SIRTAX trial, 1012 patients were randomized to treatment with SES (n = 503) or PES (n = 509). A stratified analysis of outcomes was performed according to the presence or absence of diabetes. Baseline characteristics were well balanced between SES and PES in patients with (N = 201) and without diabetes (N = 811). Clinical outcome was worse in diabetic compared with non-diabetic patients regarding death (9.0% vs. 4.1%, P = 0.004) and MACE (defined as cardiac death, myocardial infarction, or TLR; 19.9% vs. 12.7%, P = 0.007) at 2 years. Among diabetic patients, SES reduced MACE by 47% (14.8% vs. 25.8%, HR = 0.52, P = 0.05) and TLR by 61% (7.4% vs. 17.2%, HR = 0.39, P = 0.03) compared with PES at 2 years. CONCLUSION: Diabetic patients have worse prognosis than non-diabetic patients undergoing PCI with DES. Among the diabetic patient population of this trial, SES reduce repeat revascularization procedures and MACE more effectively than PES and to a similar degree as in non-diabetic patients.