Electrocardiography in Hypertensive Patients without Cardiovascular Events: A Valuable Predictor Tool?

Background: Hypertension is an important risk factor of cardiovascular (CV) disease. An early diagnosis of target organ damage could prevent major CV events. Electrocardiography (ECG) is a valuable clinical technique, with wide availability and high specificity, used in evaluation of hypertensive patients. However, the use of ECG as a predictor tool is controversial given its low sensitivity. This study aims to characterise ECG features in a hypertensive population and identify ECG abnormalities that could predict CV events. Methods: We studied 175 hypertensive patients without previous CV events during a follow-up mean of 4.0 ± 2.20 years. ECGs and pulse wave velocity were performed in all patients. Clinical characteristics and ECG abnormalities were evaluated and compared between the patients as they presented CV events. Results: Considering the 175 patients (53.14% male), the median age was 62 years. Median systolic blood pressure was 140 mmHg and diastolic blood pressure was 78 mmHg. Median PWV was 9.8 m/s. Of the patients, 39.4% were diabetic, 78.3% had hyperlipidaemia, and 16.0% had smoking habits. ECG identified left ventricular (LV) hypertrophy in 29.71% of the patients, and a LV strain pattern was present in 9.7% of the patients. Twenty-nine patients (16.57%) had a CV event. Comparative analyses showed statistical significance for the presence of a LV strain pattern in patients with CV events (p=0.01). Univariate and multivariate analysis confirmed that a LV strain pattern was an independent predictor of CV event (HR 2.66, 95% IC 1.01-7.00). In the survival analysis, the Kaplan-Meier curve showed a worse prognosis for CV events in patients with a LV strain pattern (p=0.014). Conclusion: ECG is a useful daily method to identify end-organ damage in hypertensive patients. In our study, we also observed that it may be a valuable tool for the prediction of CV events.

Tenecteplase for thrombolysis in stroke patients: Systematic review with meta-analysis.

INTRODUCTION: Alteplase is an approved treatment for acute ischemic stroke. Tenecteplase is a genetically modified form of alteplase, with lower cost and a more favourable pharmacokinetic profile allowing bolus injection. The aim of this study was to compare both drugs in adult patients with acute ischemic stroke undergoing thrombolysis. MATERIAL AND METHODS: PubMed and CENTRAL were searched for observational and experimental studies comparing both drugs in the population of interest. Additional studies were sought in clinical trial registries and by means of reference check. The efficacy outcomes of interest were functional status at 3 months, recanalization and early neurological improvement (ENI). The safety outcomes of interest were cerebral haemorrhage (ICH), symptomatic ICH and mortality. The effect measure of interest was the absolute risk difference (ARD). Effect measures for each outcome were pooled across studies using random effect models. RESULTS: Eight studies were included, involving 2031 patients. Overall, there were no differences in terms of good or excellent functional outcome (ARR = 0.07 and 0.03 respectively, p > 0.05 for both comparisons) but tenecteplase patients showed higher rates of recanalization (ARD = 0.11, 95% CI [0.01;0.20]) and ENI (ARD = 0.10, 95% CI [0.02;0.17]). There were no differences between groups in terms of ICH (ARD = -0.02, 95% CI [-0.06;0.01]), symptomatic ICH (ARD = 0.00, 95% CI [-0.01;0.02]) or death (ARD = 0.00, 95% CI [-0.03;0.03]). CONCLUSION: Tenecteplase is an alternative to alteplase for stroke thrombolysis, with lower cost and a more favourable pharmacokinetic profile.

Evaluation of vancomycin MIC creep in methicillin-resistant Staphylococcus aureus infections-a systematic review and meta-analysis.

OBJECTIVES: Vancomycin is currently the primary option treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing number of MRSA isolates with high MICs, within the susceptible range (vancomycin MIC creep), are being reported worldwide. Resorting to a meta-analysis approach, this study aims to assess the evidence of vancomycin MIC creep. METHODS: We searched for studies in the PubMed database. The inclusion criteria for study eligibility included the possibility of retrieving the reported data values of vancomycin MIC and information concerning the applied MIC methodology. RESULTS: The mean values of vancomycin MICs, of all 29 234 S. aureus isolates reported in the 55 studies included in the meta-analysis, were 1.23 mg/L (95% CI 1.13-1.33) and 1.20 mg/L (95% CI 1.13-1.28) determined by Etest and broth microdilution method, respectively. No significant differences were observed between these two methodologies. We found negative correlation between pooled mean/pooled proportion and time strata. CONCLUSIONS: We have found no evidence of the MIC creep phenomenon.

A genomic distance for assembly comparison based on compressed maximal exact matches.

Genome assemblies are typically compared with respect to their contiguity, coverage, and accuracy. We propose a genome-wide, alignment-free genomic distance based on compressed maximal exact matches and suggest adding it to the benchmark of commonly used assembly quality metrics. Maximal exact matches are perfect repeats, without gaps or misspellings, which cannot be further extended to either their left- or right-end side without loss of similarity. The genomic distance here proposed is based on the normalized compression distance, an information-theoretic measure of the relative compressibility of two sequences estimated using multiple finite-context models. This measure exposes similarities between the sequences, as well as, the nesting structure underlying the assembly of larger maximal exact matches from smaller ones. We use four human genome assemblies for illustration and discuss the impact of genome sequencing and assembly in the final content of maximal exact matches and the genomic distance here proposed.

Statistical, computational and visualization methodologies to unveil gene primary structure features.

OBJECTIVES: Gene sequence features such as codon bias, codon context, and codon expansion (e.g. trinucleotide repeats) can be better understood at the genomic scale level by combining statistical methodologies with advanced computer algorithms and data visualization through sophisticated graphical interfaces. This paper presents the ANACONDA system, a bioinformatics application for gene primary structure analysis. METHODS: Codon usage tables using absolute metrics and software for multivariate analysis of codon and amino acid usage are available in public databases. However, they do not provide easy computational and statistical tools to carry out detailed gene primary structure analysis on a genomic scale. We propose the usage of several statistical methods--contingency table analysis, residual analysis, multivariate analysis (cluster analysis)--to analyze the codon bias under various aspects (degree of association, contexts and clustering). RESULTS: The developed solution is a software application that provides a user-guided analysis of codon sequences considering several contexts and codon usage on a genomic scale. The utilization of this tool in our molecular biology laboratory is focused on particular genomes, especially those from Saccharomyces cerevisiae, Candida albicans and Escherichia coli. In order to illustrate the applicability and output layouts of the software these species are herein used as examples. CONCLUSIONS: The statistical tools incorporated in the system are allowing to obtain global views of important sequence features. It is expected that the results obtained will permit identification of general rules that govern codon context and codon usage in any genome. Additionally, identification of genes containing expanded codons that arise as a consequence of erroneous DNA replication events will permit uncovering new genes associated with human disease.