Gender-related impact on outcomes of high density lipoprotein in acute ST-elevation myocardial infarction.

BACKGROUND AND AIMS: There is rising evidence that cardioprotective functions of high-density lipoprotein (HDL) have significant impact on clinical outcomes. ST-elevation myocardial infarction (STEMI) represents a high-risk vascular condition. Whether higher HDL-cholesterol concentrations in women correspond to protective anti-oxidant properties in the setting of STEMI is unknown. METHODS: We prospectively assessed gender related differences in the anti-oxidant function of HDL, and the impact of HDL properties on mortality in 242 women and men with STEMI. Blood samples to determine HDL function and sex hormone levels were collected during primary percutaneous coronary intervention. RESULTS: Patients were stratified according to preserved anti-oxidant HDL function (HDL oxidant index (HOI) < 1) and pro-oxidant HDL (HOI≥1). Despite higher serum levels of HDL-cholesterol in postmenopausal women (48 mg/dl, IQR 42-54, versus 39 mg/dl, IQR33-47, p < 0.001 in men), the proportion of patients with pro-oxidant HDL was not different between women (35%) and men (46%, p = 0.132). Kaplan-Meier analysis revealed higher cardiovascular mortality in both women (p = 0.021) and men (p = 0.045) with pro-oxidant HDL. We identified pro-oxidant HDL as strong and independent predictor of cardiovascular mortality with an adjusted HR of 8.33 (95% CI, 1.55-44.63; p = 0.013) in women and with an adjusted HR of 5.14 (95% CI, 1.61-16.42; p = 0.006) in men. Higher levels of free sex hormones (estradiol and testosterone) were associated with pro-oxidant HDL. HDL-cholesterol levels showed no association with mortality (HR in women 1.03, 95% CI 0.96-1.11, p = 0.45 and HR in men 0.99, 95% CI 0.94-1.05, p = 0.72). CONCLUSIONS: Total HDL-cholesterol serum levels were not associated with mortality in STEMI patients. Pro-oxidant HDL was a strong and independent predictor of mortality in women and men with STEMI. The present study provides a link between sex hormones, HDL function and clinical events in STEMI patients. In clinical practice and future clinical trials, anti-oxidant properties of HDL rather than total HDL serum levels should be used for risk stratification.

Targeted multiple biomarker approach in predicting cardiovascular events in patients with diabetes.

OBJECTIVE: We hypothesised that biomarkers representing different pathophysiological pathways of atherosclerosis namely growth differentiation factor 15 (GDF-15), N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitive troponin T (hs-TnT) could enhance cardiovascular risk prediction in patients with type 2 diabetes mellitus. METHODS: This is a prospective study in 746 patients with type 2 diabetes mellitus, who were followed up for 60 months. The primary endpoint was defined as unplanned hospitalisation for cardiovascular disease or death. The prognostic performance of the biomarkers of interest (GDF-15 in comparison with NT-proBNP and hs-TnT) was evaluated in univariate as well as in stepwise Cox regression models. HRs are presented per standard unit increase. RESULTS: The primary endpoint was registered in 171 patients (22.9%). In univariate Cox regression models, GDF-15 as well as hs-TnT provided significant prognostic information. Even after adjusting for established cardiovascular risk factors, GDF-15, hs-TnT and NT-proBNP remained strong independent predictors of the endpoint (logGDF-15: HR 1.37, p<0.01, CI 1.12 to 1.68; loghs-TnT: HR 1.43, p<0.01, CI 1.13 to 1.1.82; logNT-proBNP: HR 1.45, p<0.01, CI 1.26 to 1.66). The number of elevated markers showed a strong complementarity to predict future long-term risk. Adding hs-TnT and GDF-15 to a zero model already including NT-proBNP led to a net reclassification improvement (NRI) of 33.6% (CI 16.0% to 50.8%, NRI for patients with event: 11.1% CI -4.7% to 26.6%, for patients without event: 22.5% CI 13.6% to 30.5%). CONCLUSIONS: GDF-15 and hs-TnT are strong independent cardiovascular biomarkers augmenting the predictive value of NT-proBNP in patients with diabetes.

[Health economics evaluation of magnetic resonance imaging for the staging of prostate cancer for Austria and Germany]. / Gesundheitsökonomische Evaluation der Magnetresonanzbildgebung im Staging von Prostatakarzinomen für Österreich und Deutschland.

PURPOSE: The aim of this study was the health economics analysis of MR imaging in the preoperative staging of patients with prostate carcinoma (PCa). MATERIALS AND METHODS: The health economics analysis consisted of the following steps: modeling, determination of probabilities and parameters based on a detailed literature search, evaluation using the averages of the parameters, and sensitivity analyses of the results over the ranges of values. We performed a cost-utility analysis from health insurance's perspective for Austria and Germany. The population under investigation included patients with confirmed PCa. The alternative was a decision for therapy with or without staging using MR imaging. A localized PCa was treated by prostatectomy and locally advanced PCa by radiation/hormone therapy. The result parameters were quality adjusted life years (QALYs) and costs per patient. RESULTS: The evaluation showed that MR imaging is useful regarding costs and utilities prior to radical prostatectomy which is expensive and may be associated with serious clinical consequences. The costs per patient were lower by € 2635 and the utilities were higher by 0.099 QALYs. The strategy without MR imaging for staging was dominated by the strategy using MR imaging for staging in the evaluation using the base values and in almost all sensitivity analyses. CONCLUSION: For the parameters used and almost all scenarios of the sensitivity analysis, our decision-analytic model revealed a higher cost-utility ratio for the strategy using MR imaging for the staging of PCa.

Serum uric acid is related to cardiovascular events and correlates with N-terminal pro-B-type natriuretic peptide and albuminuria in patients with diabetes mellitus.

BACKGROUND: Hyperuricemia is a risk factor for cardiovascular events and renal insufficiency. It correlates to intima-media thickness and microalbuminuria. In this study we evaluated uric acid as an independent marker for cardiac events in patients with diabetes. METHODS: In a prospective observational study we recruited 494 patients with diabetes. Patients were then followed for 12.8 months (mean follow-up) and hospitalizations as a result of cardiac events (ischaemic heart disease, arrhythmias, heart failure) were recorded. RESULTS: The median duration of diabetes was 11 ± 10.35 years. Patients were in the mean 60 ± 13 years old and mean HbA(1c) was 62 ± 13 mmol/mol (7.8 ± 3.3%). At baseline, mean uric acid was 321.2 ± 101.1 µmol/l (range 101.1-743.5 µmol/l), median N-terminal pro-B-type natriuretic peptide was 92 ± 412 pg/ml and median urinary albumin to creatinine ratio was 8 ± 361 mg/g; Uric acid significantly correlated to N-terminal pro-B-type natriuretic peptide (r = 0.237, P < 0.001) and urinary albumin:creatinine ratio (r = 0.198, P < 0.001). In a Cox regression model, including age, estimated glomerular filtration rate, gender, systolic blood pressure, smoking and alcohol consumption, uric acid was the best predictor of cardiac events (hazard ratio 1.331, confidence interval 1.095-1.616, P = 0.04). However, uric acid lost its prognostic value when the natural logarithm of N-terminal pro-B-type natriuretic peptide was added to the model. CONCLUSION: Serum uric acid is a predictor of cardiac events and correlates to N-terminal pro-B-type natriuretic peptide and albuminuria, underscoring the importance of uric acid as a cardiovascular risk marker in patients with diabetes.

[Health-economic evaluation of magnetic resonance imaging before biopsy for diagnosis of prostate cancer]. / Gesundheitsökonomische Evaluation einer Magnetresonanzbildgebung vor Biopsie zur Diagnose von Prostatakarzinomen.

PURPOSE: The aim of this study was the health-economic analysis of MR imaging in the diagnostics of suspicious prostate carcinoma (PCa) before execution of a first biopsy. MATERIALS AND METHODS: The health-economic analysis included four steps: modeling, determination of probabilities, evaluation, and sensitivity analyses. We performed an effectiveness analysis from the patient perspective as well as a cost-effectiveness and a cost-utility analysis from the health insurance perspective for Austria and Germany. The effectiveness and cost-effectiveness analysis used a hypothetical cohort of 100,000 patients. The result parameters were number of biopsies, number of detected PCa, and monetary costs. For the cost-efficiency analysis, the result parameters, quality-adjusted life years (QALYs) and costs, were calculated for an individual patient. RESULTS: The efficiency analysis showed that MRI before a first biopsy can prevent ca. 64,000 unnecessary biopsies/ 100,000 patients. The diagnostic efficiency was higher by a factor of 1.7. Due to MRI, eight PCas were additionally detected. From a health insurance perspective, MRI was not cost-effective. Extra costs of ca. 42 m. € per 100,000 patients and of 650 € per prevented biopsy were calculated. The costs per detected PCa were increased by 1395 €. The attainable QALYs were a little higher for the MRI alternative, which was therefore not dominated. CONCLUSION: Our results do not permit a clear recommendation for or against the application of MRI in the diagnostics of PCa. From the patient perspective, it is to be endorsed due to the higher medical efficiency. However, it is connected with higher health insurance costs.

Long-term outcome after thrombectomy in acute myocardial infarction.

BACKGROUND: Current data appear in favour of thrombectomy for ST-elevation myocardial infarction (STEMI). However, information on long-term outcome after thrombectomy is limited. We performed a retrospective long-term study to assess the risk of cardiac re-hospitalizations and survival after discharge from the index hospitalization for STEMI. METHODS: Patients originally randomized to percutaneous coronary intervention (PCI) with thrombectomy vs. standard PCI were included in a retrospective long-term observational study. The primary study endpoint was the combined risk for all-cause death or cardiac re-hospitalization after index discharge under optimal medical therapy. The cumulative number of cardiac hospitalization days and ventricular remodelling assessed by echocardiography and plasma biomarkers were secondary endpoints. RESULTS: Of 94 STEMI patients who had been randomized between 11/2000 and 03/2003, 89 patients consented to long-term follow-up. A total of 43 patients had been allocated to thrombectomy and 46 to standard primary PCI. The minimum follow-up time was 1115 days. There was a significantly lower risk for death or cardiac re-hospitalization for patients of the thrombectomy group (hazard ratio = 0.69, 95% CI: 0.49-0.98, P = 0.036). The incidence of recurrent myocardial infarction was not different (P = 0.343). No differences in cardiac remodelling were detected by echocardiography, with the exception that heart-type fatty acid binding protein at 53.2 +/- 17 months was lower in the thrombectomy group (P = 0.045). CONCLUSION: Thrombectomy in STEMI may decrease the long-term risk for death or cardiac re-hospitalization.

Outcome after device implantation in chronic heart failure is dependent on concomitant medical treatment.

BACKGROUND: Device implantation in chronic heart failure (CHF) for cardiac resynchronization therapy (CRT) with or without implantable cardioverter/defibrillator (ICD) is an established treatment option for symptomatic patients under medical baseline therapy. Although recommended, the need for optimization of medical therapy was never proven. As in 'the real world', medical therapy is not always up-titrated to the desirable dosages; this provides the opportunity to evaluate the impact of optimizing medical therapy in patients who had received a device therapy with proven effectiveness. MATERIALS AND METHODS: This observational cohort study retrospectively assessed the 'real life'-effect of CRT compared with that of CRT/ICD therapy and the impact of concomitant pharmacotherapy on outcome. Outcome of patients with guideline recommended renin-angiotensin system inhibitor and ss-blocker dosages was compared with that of patients who failed to reach the desired dosages. Mean follow-up for the 205 CHF (95 CRT and 110 CRT/ICD) patients was 16.8 + or - 12.4 months. RESULTS: In the total study cohort, 83 (41%) reached the combined primary endpoint of all-cause death or cardiac hospitalization [CRT group: 25 (26%), CRT/ICD group: 58 (52.7%), P < 0.001]. Multiple cox regression analysis revealed non-optimized medical therapy at follow-up [HR = 2.080 (1.166-3.710), P = 0.013] and CRT/ICD vs. CRT [HR = 2.504 (1.550-4.045), P < 0.001] as significant predictors of the primary endpoint. CONCLUSION: Our data stress the importance of professional monitoring and titration of pharmacotherapy not only in medically treated CHF patients but also in patients under device therapy by a heart failure unit or a specialized cardiologist.

[Dynamic evaluation of the effects of quality management]. / Dynamische Evaluierung der Effekte von Qualitätsmanagement.

PURPOSE: Evaluation of the effects of quality management over time at a radiology department. MATERIALS AND METHODS: Data concerning the performance of the department, entered on a monthly basis, will be compared with entries in the error report system on the basis of time series analysis (regression models taking seasons and auto-correlation effects into account). The observation period consists of 46 homogeneous monthly time pulses. RESULTS: Effects of the suggestions and the total number of reports in the quality assurance system on the performance of the department can be observed with a two-month delay. This association is statistically highly significant (p < 0.01) and, because of the procedures used, not attributable to general developmental trends, seasonal fluctuations or autoregressive processes. CONCLUSION: Evaluation of quality assurance measures is a well justified demand and should be based on the analysis of data collected from quality assurance systems operating on a continuous basis over a long period of time. The analysis of data from a radiology department shows that quality assurance is reflected in the performance of the department.

Peptide nucleic acid (PNA) is capable of enhancing hammerhead ribozyme activity with long but not with short RNA substrates.

Long RNA substrates are inefficiently cleaved by hammerhead ribozymes in trans. Oligonucleotide facilitators capable of affecting the ribozyme activity by interacting with the substrates at the termini of the ribozyme provide a possibility to improve ribozyme mediated cleavage of long RNA substrates. We have examined the effect of PNA as facilitator in vitro in order to test if even artificial compounds have facilitating potential. Effects of 12mer PNA- (peptide nucleic acid), RNA- and DNA-facilitators of identical sequence were measured with three substrates containing either 942, 452 or 39 nucleotides. The PNA facilitator enhances the ribozyme activity with both, the 942mer and the 452mer substrate to a slightly smaller extent than RNA and DNA facilitators. This effect was observed up to PNA facilitator:substrate ratios of 200:1. The enhancement becomes smaller as the PNA facilitator:substrate ratio exceeds 200:1. With the 39mer substrate, the PNA facilitator decreases the ribozyme activity by more than 100-fold, even at PNA facilitator:substrate ratios of 1:1. Although with long substrates the effect of the PNA facilitator is slightly smaller than the effect of identical RNA or DNA facilitators, PNA may be a more practical choice for potential applications in vivo because PNA is much more resistant to degradation by cellular enzymes.

Machines for automated evolution experiments in vitro based on the serial-transfer concept.

Two machine setups for automated evolution experiments in vitro are described. Both machines enable the monitoring of growing populations of RNA or DNA molecules in real time using high-sensitivity glass fiber laser fluorimeters and an automated sample handling facility for volumes in the microliter range. Growth conditions are kept constant by means of the serial-transfer technique, that is, the successive transfer of a small fraction of a growing population into a fresh solution containing no individuals prior to the transfer. The serial transfer technique was modified to work with large populations and constant growth conditions. In the single-channel evolution machine isothermal amplification reactions (Qbeta-system, 3SR, NASBA, SDA) are monitored successively in single test tubes. This machine is particularly well suited for the investigation of optimal adaptation to altered environmental conditions, as is experimentally demonstrated in the evolution of an RNA quasi-species using ribonuclease A as the selection pressure. The new variant of RNA appeared very rapidly (within approximately 80 generations) without stable intermediates, and it was selected by steadily increasing the RNaseA concentration during the serial-transfer experiment. The other machine, which is described in the second part of this article, is a consequent extension of the single-channel machine, and was designed to allow the multichannel detection of up to 960 samples simultaneously. Thus, high-throughput screening can be applied to evolution experiments. In addition to monitoring isothermal amplification reactions, it is also possible to follow PCR amplifications through thin plastic foils. Initial experiments have demonstrated the suitability of the apparatus for uniformly processing samples and for performing thermocycling.

Multichannel PCR and serial transfer machine as a future tool in evolutionary biotechnology.

As an improved strategy for producing functional macromolecules by in vitro evolutionary optimization, we propose an automated machine that can process up to 960 samples in parallel. It consists of a 960-well PCR machine with special sealed plastic reaction vessels and appropriate handling devices. We show that the heat-sealing technique does not significantly affect the activity of Taq DNA Polymerase or that of the temperature-sensitive Q beta RNA polymerase but avoids cross-contamination and evaporation of the samples. Initial experiments demonstrate the suitability of the apparatus to uniformly process the samples and to perform the thermocycling. Serial transfer of reaction products into fresh reaction solution was used to initiate further rounds of amplification as a typical experimental setup for an evolutionary biotechnology application.

Sequence analysis and location of capsid proteins within RNA 2 of strawberry latent ringspot virus.

The nucleotide sequence of the RNA 2 of a strawberry isolate (H) of strawberry latent ringspot virus (SLRSV) comprised 3824 nucleotides and contained one long open reading frame with a theoretical coding capacity of 890 amino acids equivalent to a protein of 98.8K. The N-terminal amino acid sequences of virion-derived proteins were determined by Edman degradation allowing the capsid coding regions to be located and serine/glycine cleavage sites to be identified within the polyprotein. The amino acid sequence in the capsid coding region of an isolate of SLRSV from flowering cherry in New Zealand was 97% identical to that of SLRSV-H. Except in the 3' and 5' terminal non-coding sequences, computer-based alignment and comparison algorithms did not reveal any substantial homologies between RNA 2 of SLRSV-H and the equivalent genomic segments in the nepoviruses arabis mosaic, cherry leaf roll, grapevine fanleaf, raspberry ringspot, grapevine hungarian chrome mosaic, tomato blackring, tomato ringspot, tobacco ringspot, or in the comoviruses cowpea mosaic and red clover mottle. Despite the similarities in overall genome organization, data from RNA 2 remain insufficient for unambiguous positioning of SLRSV in relation to species/genera in the Comoviridae.

Strand displacement amplification as an in vitro model for rolling-circle replication: deletion formation and evolution during serial transfer.

Strand displacement amplification is an isothermal DNA amplification reaction based on a restriction endonuclease nicking its recognition site and a polymerase extending the nick at its 3' end, displacing the downstream strand. The reaction resembles rolling-circle replication of single-stranded phages and small plasmids. The displaced sense strand serves as target for an antisense reaction and vice versa, resulting in exponential growth and the autocatalytic nature of this in vitro reaction as long as the template is the limiting agent. We describe the optimization of strand displacement amplification for in vitro evolution experiments under serial transfer conditions. The reaction was followed and controlled by use of the fluorescent dye thiazole orange binding to the amplified DNA. We were able to maintain exponential growth conditions with a doubling time of 3.0 min throughout 100 transfers or approximately 350 molecular generations by using an automatic handling device. Homology of in vitro amplification with rolling-circle replication was mirrored by the occurring evolutionary processes. Deletion events most likely caused by a slipped mispairing mechanism as postulated for in vivo replication took place. Under our conditions, the mutation rate was high and a molecular quasi-species formed with a mutant lacking internal hairpin formation ability and thus outgrowing all other species under dGTP/dCTP deficiency.

The nucleotide sequence of a satellite RNA associated with strawberry latent ringspot virus.

The nucleotide sequence of a satellite RNA associated with a strawberry isolate (H) of strawberry latent ringspot nepovirus (SLRSV) was determined from cDNA copies and the 5' end sequence was deduced from directly sequenced virion RNA. At the 3' end a poly(A) sequence was identified. A long open reading frame encoding a polypeptide of 331 amino acids (M(r) 36488) was determined. Sequence comparisons showed that SLRSV satellite RNA has no extensive homology with other sequences in the GenEmbl and Swiss-Prot databases.