Characterization of virus‒host recombinant variants of the hepatitis E virus.

Unlabelled: Hepatitis E virus is a single-strand, positive-sense RNA virus that can lead to chronic infection in immunocompromised patients. Virus-host recombinant variants (VHRVs) have been described in such patients. These variants integrate part of human genes into the polyproline-rich region that could introduce new post-translational modifications (PTMs), such as ubiquitination.

A fully automated system using transcription-mediated amplification for the molecular diagnosis of hepatitis E virus in human blood and faeces.

Background And Objectives: We evaluated the performance of the Procleix HEV RNA assay implemented on the Panther automated platform for detecting HEV RNA.

Study Design And Results: Analytical specificity was 100% and there was no cross contamination, as assessed by assaying 122 plasma samples from HEV RNA-negative blood donors. The limits of detection were determined by Probit analysis with the WHO HEV standard (HEV subtype 3a) and subtype 3f and 3c reference strains.

Detection and quantification of HIV-1 RNA with a fully automated transcription-mediated-amplification assay.

Background: Nucleic acid testing is the major method used to monitor HIV viral load. Commercial systems based on real-time PCR assays are available for high-volume centralized laboratory testing, but they are not fully automated.

Objectives And Study Design: We have compared the diagnostic performance of the Hologic Aptima HIV-1 Quant Dx assay (Aptima) (based on real-time TMA) on the Panther instrument, a fully-automated random access platform, to that of, the Roche Cobas Ampliprep Cobas TaqMan (CAP/CTM) HIV-1 version 2.

Analytical performance of the VERIS MDx system HCV assay for detecting and quantifying HCV RNA.

Background: The diagnosis of HCV relies on the detection of viral RNA.

Objective: To evaluate the performance of the VERIS/MDx System HCV Assay, a new automated system for quantifying HCV RNA, and to compare with the COBAS Ampliprep/COBAS Taqman™ (CAPCTM) HCV Test version 2.0.

Performance of a completely automated system for monitoring CMV DNA in plasma.

Background: Completely automated systems for monitoring CMV-DNA in plasma samples are now available.

Objectives: Evaluate analytical and clinical performances of the VERIS™/MDx System CMV Assay(®).

Study Design: Analytical performance was assessed using quantified quality controls.

Analytical sensitivity of three real-time PCR assays for measuring subtype B HIV-1 RNA.

Background: Lack of HIV RNA during antiretroviral therapy (ART) is regarded as a desirable outcome. Commercial assays of HIV virus load now need to detect virus RNA concentrations below 50 c/ml and several of them have claimed a limit of detection (LOD) of 20-45 c/ml.

Objectives And Study Design: We have compared the performances of three commercial assays of HIV RNA, the Abbott RealTime HIV-1, the Qiagen Artus RG HIV-1 and the Roche Cobas Ampliprep Cobas TaqMan (CAPCTM) HIV-1 vs 2.

Prospective evaluation of a new automated nucleic acid extraction system using routine clinical respiratory specimens.

The aim of the study was to evaluate the MagNA Pure 96™ nucleic acid extraction system using clinical respiratory specimens for identifying viruses by qualitative real-time PCR assays. Three extraction methods were tested, that is, the MagNA Pure LC™, the COBAS Ampliprep™, and the MagNA Pure 96™ with 10-fold dilutions of an influenza A(H1N1)pdm09 sample. Two hundred thirty-nine respiratory specimens, 35 throat swabs, 164 nasopharyngeal specimens, and 40 broncho-alveolar fluids, were extracted with the MagNA Pure 96™ and the COBAS Ampliprep™ instruments.

A new highly automated extraction system for quantitative real-time PCRs from whole blood samples: routine monitoring of opportunistic infections in immunosuppressed patients.

Background: Rapid, high throughput extraction systems are needed to monitor viral infections in immunosuppressed patients.

Objectives: Evaluate the performance of the MagNA Pure 96™ extraction system, and compare it to the COBAS Ampliprep™ for quantitative real-time PCR from whole blood samples.

Study Design: Compare the MagNA Pure LC™, COBAS Ampliprep™ and MagNA Pure 96™ using ten-fold dilutions of blood samples containing cytomegalovirus.

The effects of inflammation on heart rate and rhythm in a canine model of cardiac surgery.

Background: Heart rate (HR) and rhythm disturbances are common after cardiac surgery. This study tests the hypothesis that the inflammation caused by cardiac surgery is an underlying mechanism for postoperative changes in HR, rhythm, and HR variability (HRV).

Method And Results: Normal canines (n = 6 per group) were divided into 4 groups: (1) anesthesia, (2) sternotomy and pericardiotomy, (3) atriotomy, and (4) corticosteroids combined with an atriotomy.

Evaluation of the QIAsymphony™ SP and Artus™ RealTime extraction-quantification systems for measuring HIV-1 virus load.

Background: Automated HIV-1 RNA extraction and its quantification by real-time PCR assays provide improved sample processing and better analytical performances. The new Artus HIV-1 RealTime assay can be performed after automated extraction with the Qiagen Qiasymphony robot.

Objectives And Study Design: To evaluate the sensitivity, reproducibility, linearity, ability to detect HIV-1 subtypes of the Qiagen Qiasymphony and RealTime Artus HIV-1 assay system and to compare with the Roche Cobas Ampliprep Cobas TaqMan assay, vs 2.

Diagnosis of multiple infarcts from complex electrocardiograms during normal rhythm, left bundle-branch block, and ventricular pacing.

Introduction: Because of better treatment of chronic coronary artery disease, patients with multiple ischemic insults are living longer and requiring long-term management. Electrocardiograms (ECGs) in patients with multiple myocardial infarctions (MMIs) are a challenge to the clinician or cardiologist. This is because second myocardial infarctions (MIs) often modify or obscure the ECG effects of the first MI and vice versa.

Atrial fibrillation propagates through gaps in ablation lines: implications for ablative treatment of atrial fibrillation.

Background: It has been hypothesized that atrial lesions must be transmural to successfully cure atrial fibrillation (AF). However, ablation lines often do not extend completely across the atrial wall.

Objective: The purpose of this study was to determine the effect of residual gaps on conduction properties of atrial tissue.

Pulmonary vein isolation and the Cox maze procedure only partially denervate the atrium.

Objectives: The effects of ablation lines on myocardial innervation and response to autonomic stimuli are unclear. This study examined the effects of radiofrequency ablation on atrial autonomic innervation and compared pulmonary vein isolation and the biatrial Cox maze procedure.

Methods: In 12 acute canines right and left vagosympathetic trunks and right and left stellate ganglia were isolated.

Detection and quantitation of HCV RNA using real-time PCR after automated sample processing.

There is considerable evidence that the loss of hepatitis C virus (HCV) RNA during the first 3 months of treatment with pegylated interferon plus ribavirin is a prognostic marker of response to therapy. Real-time polymerase chain reaction (PCR) assays for quantifying HCV RNA in plasma or serum are now commercially available. The extraction of HCV RNA can also be automated.

The early repolarization variant--normal or a marker of heart disease in certain subjects.

The theory is advanced that the early repolarization variant may not always be benign and that it can become a substrate for ventricular arrhythmias, sudden death, and hypercontractility cardiomyopathy in some subjects, including certain high-performance athletes. In addition, it is suggested that it likely represents part of a spectrum of cardiovascular anomalies related to nonischemic ST elevation including Brugada syndrome, and that it may also have a molecular genetic origin of variable penetrance.

The early repolarization variant--an electrocardiographic enigma with both QRS and J-STT anomalies.

A detailed description of the electrocardiogram of the early repolarization variant, including its most common morphological variations is presented. Included is a recently identified anomaly of the QRS complex, which has not previously been reported. Ventricular activation data is presented to explain the unique QRS changes.

Spatial and temporal stability of the dominant frequency of activation in human atrial fibrillation.

Purpose: Intraoperative activation sequence mapping during atrial fibrillation (AF) is difficult because of the complexity of the data. The data analysis is time consuming, and picking activation times can be ambiguous. The purpose of this study was to determine whether mapping in the frequency domain during AF can be used to rapidly locate the region and assess the stability of the dominant frequency.

Left ventricular muscle band (VMB): thoughts on its physiologic and clinical implications.

Although the ventricular muscle band (VMB) is formed by one continuous band of myocardium and there is some evidence to suggest that it may contract sequentially along its course from the right ventricle, through the septum, then along its basoapical left ventricular spiral, the structure is not activated in this sequence. Activation as programmed by the fully developed Purkinje system proceeds broadly and directly from endocardium to epicardium and from apex to base. Although not activated sequentially along its course, the band may still contract and relax sequentially if there is a progressive lengthening of the contraction duration in association with a nonuniform lengthening of the cardiac fiber action potential (repolarization) duration.

Importance of geometry and refractory period in sustaining atrial fibrillation: testing the critical mass hypothesis.

Background: The critical mass hypothesis for atrial fibrillation (AF) was proposed in 1914. There has never been a systematic investigation defining the relationship between tissue geometry and AF. The purpose of this study was to determine the association among the probability of maintaining AF and the width, area, weight, effective refractory period (ERP), and wavelength in atrial tissue.

Inflammation of atrium after cardiac surgery is associated with inhomogeneity of atrial conduction and atrial fibrillation.

Background: Atrial fibrillation (AF) is common after cardiac surgery. Abnormal conduction is an important substrate for AF. We hypothesized that atrial inflammation alters atrial conduction properties.

Surgical treatment of atrial fibrillation: predictors of late recurrence.

Objective: The Cox maze procedure was introduced in 1987 for the treatment of atrial fibrillation. This study evaluated the predictors of late atrial fibrillation recurrence in 276 consecutive patients who underwent this procedure at our institution.

Methods: From 1987 through June 2003, 276 patients (79 female and 197 male patients; mean age, 55 +/- 11 years) underwent the Cox maze procedure.

Atrial tachyarrhythmias after the maze procedure: incidence and prognosis.

Background: The Maze procedure restores normal sinus rhythm in the majority of patients. However, atrial tachyarrhythmias (ATA) are a common early complication after the operation. The purpose of this study was to define the incidence and natural history of ATA after the Maze procedure.

The long-term outcome of patients with coronary disease and atrial fibrillation undergoing the Cox maze procedure.

Background: A significant number of patients presenting for coronary revascularization have chronic atrial fibrillation. Although the Cox maze III procedure is the gold standard for the surgical treatment of this arrhythmia, few of these patients undergo atrial fibrillation operations at the time of their coronary bypass grafting. This study examined the long-term outcome of patients with ischemic heart disease who underwent the Cox maze procedure at our institution.

The Cox maze III procedure for atrial fibrillation: long-term efficacy in patients undergoing lone versus concomitant procedures.

Background: For the last decade, the Cox maze III procedure has been available for the treatment of atrial fibrillation. It is unknown whether the operation has similar efficacy in patients with lone atrial fibrillation compared with that in patients with atrial fibrillation associated with coronary, valve, or congenital heart disease. This study examined the long-term outcome of patients who underwent this procedure either as a lone operation or as a concomitant procedure.