Vascular remodeling in adults after coarctation repair: impact of descending aorta stenosis and age at surgery

Background  

Patients after successful repair of coarctation of aorta (CoAo) are at risk of hypertension at rest and associated end-organ damage. The aim of the study was to assess arterial stiffness and function in adults after coarctation repair in relation to descending aorta (AoD) residual coarctation and patient’s age at operation.     

Injury and differentiation following inhibition of mitochondrial respiratory chain complex IV in rat oligodendrocytes

Oligodendrocyte lineage cells are susceptible to a variety of insults including hypoxia, excitotoxicity, and reactive oxygen species. Demyelination is a well‐recognized feature of several CNS disorders including multiple sclerosis, white matter strokes, progressive multifocal leukoencephalopathy, and disorders due to mitochondrial DNA mutations. Although mitochondria have been implicated in the demise of oligodendrocyte lineage cells, the consequences of mitochondrial respiratory chain defects have not been examined. We determine the in vitro impact of established inhibitors of mitochondrial respiratory chain complex IV or cytochrome c oxidase on oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes as well as on differentiation capacity of OPCs from P0 rat. Injury to mature oligodendrocytes following complex IV inhibition was significantly greater than to OPCs, judged by cell detachment and mitochondrial membrane potential (MMP) changes, although viability of cells that remained attached was not compromised. Active mitochondria were abundant in processes of differentiated oligodendrocytes and MMP was significantly greater in differentiated oligodendrocytes than OPCs. MMP dissipated following complex IV inhibition in oligodendrocytes. Furthermore, complex IV inhibition impaired process formation within oligodendrocyte lineage cells. Injury to and impaired process formation of oligodendrocytes following complex IV inhibition has potentially important implications for the pathogenesis and repair of CNS myelin disorders. © 2010 Wiley‐Liss, Inc.     

Correlation between EGFR Y1068 tyrosine phosphorylation and AP-1 activation by tumor promoter 12-O-tetradecanoylphorbol-13-acetate in mouse skin

The mouse skin carcinogenesis is unique model for our understating of molecular events leading to tumor development. The tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) activates a variety of signaling pathways, including MAPK/AP-1. In this study, we examined the time course of EGFR phosphorylation and AP-1 activation in mouse epidermis after topical application of a single 10 nmol dose of TPA. Remarkable differences in the phosphorylation kinetics of EGFR tyrosine residues were observed. While the maximal level of Y1068 tyrosine phosphorylation occurred 4 h after TPA treatment, the Y1173 residue phosphorylation was initially down-regulated, and reached the highest level after 24 h. Phosphorylation of Y1068 tyrosine was correlated with AP-1 activation and c-Jun N-terminal kinase (JNK) activity. These results indicate that the stimulation of AP-1 in mouse epidermis by TPA may be the effect of EGFR activation, but not all tyrosine residues forming its catalytic center are equally involved in this process.     

Prognostic value of angiographic markers of myocardial reperfusion in patients treated with primary coronary angioplasty for anterior wall acute myocardial infarction

BACKGROUND: Modern therapy of acute myocardial infarction (AMI) is aimed at rapid and persisting restoration of blood flow in an infarct-related artery (IRA). However, in some patients myocardial reperfusion is not achieved in spite of effective IRA recanalisation. Myocardial Blush Grade (MBG) is one of the angiographic markers useful for the detection of this phenomenon. AIM: To assess the prognostic value of MBG in patients with anterior AMI treated with primary angioplasty. METHODS: The study group consisted of 104 patients (74 males, 30 females, mean age 62+/-13 years) treated with primary angioplasty due to anterior ST-segment elevation AMI. MBG was assessed after the procedure. The mortality and major cardiovascular event (MACE) rates were analysed one and six months after AMI. RESULTS: Patients with preserved myocardial reperfusion following angioplasty (MBG 2-3, n=64 (61.5%)) had a trend towards lower one-month mortality and significantly reduced six-month mortality compared with 40 (38.5%) patients with an impaired (MBG 0-1) myocardial reperfusion (3% vs 12.5%, NS; and 6.25% vs 20%, p<0.05, respectively). The rate of MACE was significantly lower in patients with rather than without reperfusion both after one and six months of follow-up (9.4% vs 27.5%, p=0.027 and 12.5% vs 42.5%, p<0.001, respectively). Compared with patients with a high MBG score, patients with altered reperfusion more frequently had diabetes (30% vs 12.5%, p=0.04), hypertension (67.5% vs 45%, p=0.043), longer time from the onset of symptoms to balloon inflation (355.9+/-199 min vs 215.5+/-113 min, p<0.001) and lower left ventricular ejection fraction, measured 3 days after AMI (43.3%+/-8 vs 47.4%+/-9, p=0.02). CONCLUSIONS: MBG has a significant prognostic value in patients with anterior AMI treated with primary angioplasty. Diabetes, hypertension and long delay of treatment are associated with the impairment of myocardial reperfusion.     

Effects of direct stenting on epicardial and myocardial perfusion in patients with acute ST segment elevation myocardial infarction

BACKGROUND: Results of studies comparing direct stenting (DS) with conventional stenting (CS) after balloon predilatation in patients with acute myocardial infarction (MI) have been reported in the past, however they are conflicting. There are only few randomised studies that aim to answer whether DS improves epicardial and myocardial patency. AIM: To assess the effects of DS on epicardial and myocardial patency in patients with acute MI. METHODS: Consecutive patients with acute MI were randomised either to DS or CS strategy. Clinical exclusion criteria were as follows: clinical and electrocardiographic features of reperfusion, pulmonary oedema, cardiogenic shock, contradictions to coronarography, allergy to aspirin, ticlopidine, clopidogrel, heparin and stainless steel. Angiographic exclusion criteria were as follows: lesion <50% with correct patency in the infarct-related artery (IRA), lesion in the left main coronary artery, previously performed percutaneous coronary intervention in the target vessel, diameter of the IRA <2 mm or >4 mm. We assessed epicardial patency according to the TIMI (thrombolysis in myocardial infarction) scale and myocardial patency according to the TMPG (TIMI myocardial perfusion grade) scale. In addition, we analysed ST segment resolution in 12-lead electrocardiography (ECG). The ECG was performed before and 30 minutes after PCI. RESULTS: We analysed 300 consecutive patients with acute ST segment elevation MI. After exclusion of patients not suitable for the study design, the DS group comprised 110 patients and the CS group - 107 patients. Clinical and angiographic results were similar in both groups. Initial TIMI 0 (48.2% vs. 43.0%), initial TIMI 3 (31.8% vs. 28.0%), initial TMPG 0-1 (77.3% vs. 78.5%), final TIMI 3 (95.5% vs. 93.5%) and final TMPG 2-3 (68.2% vs. 60.8%) were similar in the DS and CS groups, respectively (p=NS). The incidence of no-reflow phenomenon was comparable in both groups (4.5% vs. 6.5%, NS). The inclusive rate of no-reflow phenomenon plus worsening patency in the IRA were 6.4% vs. 10.3% in the DS and CS groups respectively. The ST segment resolution > or = 50% was 58.1% in the DS group and 56.1% in the CS group (NS). CONCLUSIONS: Direct stenting does not significantly improve epicardial and myocardial patency in an unselected group of patients with acute ST segment elevation MI.     

Persistent platelet activation is related to very early cardiovascular events in patients with acute coronary syndromes

INTRODUCTION: Persistent platelet function while on antiplatelet therapy affects outcomes in patients with acute coronary syndromes (ACS). AIM: To evaluate whether platelet reactivity measured by collagen-epinephrine (CEPI) or collagen-ADP (CADP) closure times (CT) with Platelet Function Analyzer 100 (PFA-100) is related to very early, in-hospital cardiovascular events in patients with ACS. METHODS: The study included 91 patients with ACS undergoing percutaneous coronary intervention (PCI) with stent implantation who were treated with aspirin and clopidogrel. Patients were stratified in accordance with both CEPI-CT (<190 s or >190 s), reflecting aspirin resistance, and our own cut-off point for CADP-CT measured at a mean of 6 days after admission. In-hospital events included re-infarction, cardiac arrest, recurrent angina, severe arrythmias, pulmonary oedema and cardiogenic shock. RESULTS: Patients were divided into 4 study groups: group 1 with CADP-CT <104 s (n=10, 11.0%), group 2 with CEPI-CT <190 s (n=10, 11.0%), group 3 with CADP-CT <104 s and CEPI-CT <190 s (n=9, 9.9%) and a control group with both CT values above the cut-off limits (n=62, 68.1%). The baseline clinical characteristics and received treatment of each subgroup were similar. A test for a trend between controls, group 1 or 2 and group 3 disclosed statistical significance (p <0.001). When analysed separately, only patients from group 3 had a higher incidence of negative outcomes compared to controls (p <0.005; relative risk RR - 9.0; 95% CI 2.4-33.9). CONCLUSIONS: Enhanced platelet function after PCI when measured under high shear rates by both PFA-100 cartridges is independently associated with the most unfavourable in-hospital clinical outcome.     

Fe-Doped Barium Lanthanum Titanate as a Competitor to Other Lead-Free Piezoelectric Ceramics

Multiferroic solid solutions of Ba_1−xLa_xTi_1−x/4O₃ and iron (BLFT) were synthesized using the conventional mixed oxide method. The dependence of the piezoelectric coefficients on Fe content in BLFT ceramics was determined by the quasi-static and resonance method. The results indicate that 0.3 mol% addition of Fe³⁺ ions to the ceramic structure increased the value of the piezoelectric parameter d₃₃ to the maximum of 159 pC/N. This puts BLFT ceramics among other good-quality and lead-free piezoelectric ceramics. A major enhancement of dielectric properties related to the manipulation of Fe content in the barium lanthanum titanate (BLT) ceramics system is reported as well.     

Subacute stent thrombosis following coronary angioplasty: incidence and risk factors

BACKGROUND: Subacute stent thrombosis was a significant complication in the early years of coronary stenting, often leading to myocardial infarction, need for urgent surgery or even death. The introduction of intracoronary ultrasound enabled the identification and proper treatment of the main causes of stent thrombosis, reducing the rate of this complication to 1%. AIM: To identify risk factors of subacute stent thrombosis. METHODS: Data concerning 845 procedures with a single stent implantation in patients with stable or unstable angina, undergoing this procedure between 1998 and 2000, were analysed. RESULTS: Subacute stent thrombosis occurred in 13 (1.54%) patients. Risk factors for this complication included urgent procedures (so-called bailout stenting), improper pre-treatment with drugs ("ad hoc" procedures), dissection uncovered by stent, and poor final result of procedure (higher degree of residual stenosis). The majority of these patients developed myocardial infarction in spite of the fact that the patency of stented vessel was quickly achieved in all but one patient. CONCLUSIONS: Urgent stenting, improper drug pre-treatment and suboptimal result of the procedure are the risk factors of subacute stent thrombosis.