Do activities of cytochrome P450 (CYP)3A, CYP2D6 and P-glycoprotein differ between healthy volunteers and HIV-infected patients?

BACKGROUND: In inflammation and infection, cytochrome P450 (CYP) enzyme activities are down-regulated. Information on possible discrepancies in activities of CYP enzymes and drug transporters between HIV-infected patients and healthy people is limited. METHODS: We used midazolam, dextromethorphan and digoxin as in vivo phenotyping probes for CYP3A (CYP3A4/5), CYP2D6 and P-glycoprotein activities, respectively, and compared these activities between 12 healthy Caucasian volunteers and 30 treatment-naive HIV-infected patients. RESULTS: Among the HIV-infected patients, the overall CYP3A activity (apparent oral midazolam clearance) was approximately 50% of the activity observed in healthy volunteers (point estimate 0.490, 90% confidence interval [CI] 0.377-0.638). The CYP2D6 activity (plasma ratio area under the curve [AUC]; AUC(dextromethorphan)/AUC(dextrorphan)) was essentially unchanged (point estimate 1.289, 90% CI 0.778-2.136). P-glycoprotein activity was slightly lower in patients (digoxin maximum concentration point estimate 1.304, 90% CI 1.034-1.644). CONCLUSIONS: The overall CYP3A activity was approximately 50% lower in HIV-infected patients than in healthy volunteers. The CYP2D6 activity was highly variable, but, on average was not different between groups, whereas a marginally lower P-glycoprotein activity was observed in treatment-naive HIV-infected patients

Improved Stratification of Autonomic Regulation for risk prediction in post-infarction patients with preserved left ventricular function (ISAR-Risk)

Aims To investigate the combination of heart rate turbulence (HRT) and deceleration capacity (DC) as risk predictors in post-infarction patients with left ventricular ejection fraction (LVEF) > 30%. Methods and results We enrolled 2343 consecutive survivors of acute myocardial infarction (MI) (30% (cumulative 5-year mortality rates of 37.9% and 7.8%, respectively). Among patients with LVEF > 30%, SAF identified another high-risk group of 117 patients with 37 deaths (cumulative 5-year mortality rates of 38.6% and 6.1%, respectively). Merging both high-risk groups (i.e. LVEF ≤ 30% and/or SAF) doubled the sensitivity of mortality prediction compared with LVEF ≤ 30% alone (21.1% vs. 42.1%, P 30%, SAF identifies a high-risk group equivalent in size and mortality risk to patients with LVEF ≤ 30%

Plasma TF activity predicts cardiovascular mortality in patients with acute myocardial infarction

<p>Abstract</p> <p>Objectives and Background</p> <p>Tissue factor (TF) contributes to thrombosis following plaque disruption in acute coronary syndromes (ACS). Aim of the study was to investigate the impact of plasma TF activity on prognosis in patients with ACS.</p> <p>Methods and Results</p> <p>One-hundred seventy-four patients with unstable Angina pectoris (uAP) and 112 patients with acute myocardial infarction (AMI) were included with a mean follow up time of 3.26 years. On admission, plasma TF activity was assessed. Patients were categorized into 2 groups: a high-TF activity group with TF >24 pmol/L and low TF activity group with TF ≤ 24 pmol/L. Fifteen cardiovascular deaths occurred in the uAP group and 16 in the AMI group. In AMI TF activity was 24,9 ± 2,78 pmol/l (mean ± SEM) in survivors and 40,9 ± 7,96 pmol/l in nonsurvivors (P = 0.024). In uAP no differences were observed (25.0 ± 8.04 pmol/L nonsurvivors vs. 25.7 ± 2.14 pmol/L survivors; P = 0.586). Kaplan-Meier estimates of survival at 3.26 years regarding TF activity in AMI were 81.3% and 92.2% with an hazard ratio of 3.02 (95% CI [1.05–8.79], P = 0.03). The Cox proportional hazards model adjusting for correlates of age and risk factors showed that plasma TF activity was an independent correlate of survival (hazard ratio 9.27, 95% CI [1.24–69.12], P = 0.03). In an additional group of patients with uAP and AMI, we identified circulating microparticles as the prevailing reservoir of plasma TF activity in acute coronary syndromes.</p> <p>Conclusion</p> <p>Systemic TF activity in AMI has an unfavorable prognostic value and as a marker for dysregulated coagulation may add to predict the atherothrombotic risk.</p

Biodegradable polymer drug-eluting stents reduce the risk of stent thrombosis at 4 years in patients undergoing percutaneous coronary intervention: a pooled analysis of individual patient data from the ISAR-TEST 3, ISAR-TEST 4, and LEADERS randomized trials

Aims The efficacy of durable polymer drug-eluting stents (DES) is delivered at the expense of delayed healing of the stented vessel. Biodegradable polymer DES aim to avoid this shortcoming and may potentially improve long-term clinical outcomes, with benefit expected to accrue over time. We sought to compare long-term outcomes in patients treated with biodegradable polymer DES vs. durable polymer sirolimus-eluting stents (SES). Methods and results We pooled individual patient data from three large-scale multicentre randomized clinical trials (ISAR-TEST 3, ISAR-TEST 4, and LEADERS) comparing biodegradable polymer DES with durable polymer SES and assessed clinical outcomes during follow-up through 4 years. The efficacy endpoint of interest was target lesion revascularization and the safety endpoint of interest was definite stent thrombosis. Out of 4062 patients included in the present analysis, 2358 were randomly assigned to treatment with biodegradable polymer DES (sirolimus-eluting, n= 1501; biolimus-eluting, n= 857) and 1704 patients to durable polymer SES. No heterogeneity across the trials was observed in analyses of the primary and secondary endpoints. At 4 years, the risk of target lesion revascularization was significantly lower among patients treated with biodegradable polymer DES vs. durable polymer SES (hazard ratio 0.82, 95% CI 0.68-0.98, P= 0.029). In addition, the risk of stent thrombosis was significantly reduced with biodegradable polymer DES vs. durable polymer SES (hazard ratio 0.56, 95% CI 0.35-0.90, P= 0.015), driven by a lower risk of very late stent thrombosis (hazard ratio 0.22, 95% CI 0.08-0.61, P= 0.004). In keeping with this, in landmark analysis between 1 and 4 years, the incidence of myocardial infarction was lower for patients treated with biodegradable polymer DES vs. durable polymer SES (hazard ratio 0.59, 95% CI 0.73-0.95, P= 0.031). Conclusion Biodegradable polymer DES improve safety and efficacy compared with durable polymer SES during long-term follow-up to 4 year

Biodegradable Polymer Versus Permanent Polymer Drug-Eluting Stents and Everolimus- Versus Sirolimus-Eluting Stents in Patients With Coronary Artery Disease 3-Year Outcomes From a Randomized Clinical Trial

ObjectivesThe aim of this study was to compare the 3-year efficacy and safety of biodegradable polymer with permanent polymer stents and of everolimus-eluting stents (EES) with sirolimus-eluting stents (SES).BackgroundBiodegradable polymer drug-eluting stents (DES) offer potential for enhanced late outcomes in comparison with permanent polymer stents. In addition, there is increasing interest in the comparison of EES (Xience, Abbott Vascular, Abbott Park, Illinois) versus SES (Cypher, Cordis Corporation, Miami Lakes, Florida).MethodsThe ISAR-TEST 4 (Intracoronary Stenting and Angiographic Results: Test Efficacy of 3 Limus-Eluting Stents-4) was a randomized clinical trial with broad inclusion criteria, enrolling 2,603 patients at 2 clinics in Munich, Germany. Patients were randomized to either biodegradable polymer (n = 1,299) or permanent polymer stents (n = 1,304); patients treated with permanent polymer stents were randomly allocated to EES (n = 652) or SES (n = 652). The primary endpoint was the composite of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization.ResultsClinical events continued to accrue at a low rate out to 3 years in all groups. Overall, there was no significant difference between biodegradable polymer and permanent polymer DES with regard to the primary endpoint (20.1% vs. 20.9%, hazard ratio [HR]: 0.95, 95% confidence interval [CI]: 0.80 to 1.13; p = 0.59). Rates of definite/probable stent thrombosis were also similar in both groups (1.2% vs. 1.7%, respectively; HR: 0.71, 95% CI: 0.37 to 1.39; p = 0.32). In patients treated with permanent polymer stents, EES were comparable to SES with regard to the primary endpoint (19.6% vs. 22.2%, respectively; HR: 0.87, 95% CI: 0.68 to 1.11; p = 0.26) as well as definite/probable stent thrombosis (1.4% vs. 1.9%, HR: 0.75, 95% CI: 0.32 to 1.78; p = 0.51).ConclusionsBiodegradable polymer and permanent polymer DES are associated with similar clinical outcomes at 3 years. In addition, EES are comparable to SES in terms of overall clinical efficacy and safety. (Intracoronary Stenting and Angiographic Results: Test Efficacy of 3 Limus-Eluting STents [ISAR-TEST 4]: Prospective, Randomized Trial of 3-limus Agent-eluting Stents With Different Polymer Coatings; NCT00598676

Acute Beneficial Hemodynamic Effects of a Novel 3D-Echocardiographic Optimization Protocol in Cardiac Resynchronization Therapy

Post-implantation therapies to optimize cardiac resynchronization therapy (CRT) focus on adjustments of the atrio-ventricular (AV) delay and ventricular-to-ventricular (VV) interval. However, there is little consensus on how to achieve best resynchronization with these parameters. The aim of this study was to examine a novel combination of doppler echocardiography (DE) and three-dimensional echocardiography (3DE) for individualized optimization of device based AV delays and VV intervals compared to empiric programming.25 recipients of CRT (male: 56%, mean age: 67 years) were included in this study. Ejection fraction (EF), the primary outcome parameter, and left ventricular (LV) dimensions were evaluated by 3DE before CRT (baseline), after AV delay optimization while pacing the ventricles simultaneously (empiric VV interval programming) and after individualized VV interval optimization. For AV delay optimization aortic velocity time integral (AoVTI) was examined in eight different AV delays, and the AV delay with the highest AoVTI was programmed. For individualized VV interval optimization 3DE full-volume datasets of the left ventricle were obtained and analyzed to derive a systolic dyssynchrony index (SDI), calculated from the dispersion of time to minimal regional volume for all 16 LV segments. Consecutively, SDI was evaluated in six different VV intervals (including LV or right ventricular preactivation), and the VV interval with the lowest SDI was programmed (individualized optimization).EF increased from baseline 23±7% to 30±8 (p<0.001) after AV delay optimization and to 32±8% (p<0.05) after individualized optimization with an associated decrease of end-systolic volume from a baseline of 138±60 ml to 115±42 ml (p<0.001). Moreover, individualized optimization significantly reduced SDI from a baseline of 14.3±5.5% to 6.1±2.6% (p<0.001).Compared with empiric programming of biventricular pacemakers, individualized echocardiographic optimization with the integration of 3-dimensional indices into the optimization protocol acutely improved LV systolic function and decreased ESV and can be used to select the optimal AV delay and VV interval in CRT

Comparative expression pattern of Matrix-Metalloproteinases in human glioblastoma cell-lines and primary cultures

<p>Abstract</p> <p>Background</p> <p>Glioblastomas (GBM), the most frequent malignant brain tumors in adults, are characterized by an aggressive local growth pattern and highly invasive tumor cells. This invasion is facilitated by expression of matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases. They mediate the degradation of protein components of the extracellular matrix. Twenty-three family members are known. Elevated levels of several of them have been reported in GBM. GBM cell-lines are used for <it>in vitro </it>studies of cell migration and invasion. Therefore, it is essential to know their MMP expression patterns. Only limited data for some of the cell-lines are published, yet. To fill the gaps in our knowledge would help to choose suitable model systems for analysis of regulation and function of MMPs during GBM tumorigenesis, cell migration and invasion.</p> <p>Findings</p> <p>We analysed MMP-1, -8, -9, -10, -11, -13, -17, -19, -20, -21, -23, -24, -26, -27, and MMP-28 expression in seven GBM cell-lines (SNB-19, GaMG, U251, U87, U373, U343, U138) and in four primary cell cultures by semiquantitative RT-PCR, followed changes in the MMP expression pattern with increasing passages of cell culture and examined the influence of TNF-α and TGF-β1 stimulation on the expression of selected MMPs in U251 and U373 cells.</p> <p>MMP-13, -17, -19 and -24 were expressed by all analyzed cell-lines, whereas MMP-20 and MMP-21 were not expressed by any of them. The other MMPs showed variable expression, which was dependent on passage number. Primary cells displayed a similar MMP-expression pattern as the cell-lines. In U251 and U373 cells expression of MMP-9 and MMP-19 was stimulated by TNF-α. MMP-1 mRNA expression was significantly increased in U373 cells, but not in U251 cells by this cytokine. Whereas TGF-β1 had no impact on MMP expression in U251 cells, it significantly induced MMP-11 and MMP-24 expression in U373 cells.</p> <p>Conclusions</p> <p>Literature-data and our own results suggest that the expression pattern of MMPs is highly variable, dependent on the cell-line and the cell-culture conditions used and that also regulation of MMP expression by cytokines is cell-line dependent. This is of high impact for the transfer of cell-culture experiments to clinical implementation.</p