Digoxin in Patients With Advanced Heart Failure and Sinus Rhythm Submitted to Cardiac Resynchronization Therapy-Is There Any Benefit?

ABSTRACT: Digoxin (DG) use in patients with heart failure with reduced ejection fraction (HFrEF) and sinus rhythm remains controversial. We aimed to assess the prognostic effect of DG in patients in sinus rhythm submitted to cardiac resynchronization therapy (CRT). Retrospective study including 297 consecutive patients in sinus rhythm, with advanced HFrEF submitted to CRT. Patients were divided into 2 groups: with DG and without DG (NDG). During a mean follow-up of 4.9 ± 3.4 years, we evaluated the effect of DG on the composite end point defined as cardiovascular hospitalization, progression to heart transplantation, and all-cause mortality. Previous to CRT, 104 patients (35%) chronically underwent DG and 193 patients (65%) underwent NDG treatment. The 2 groups did not differ significantly regarding HF functional class, HF etiology, QRS, and baseline left ventricular ejection fraction. The proportion of responders to CRT was similar in both groups (54% in DG vs. 56% in NDG; P = 0.78). During the long-term follow-up period, the primary end point occurred in a higher proportion in DG patients (67 vs. 48%; P = 0.002). After adjustment for potential confounders, DG use remained as an independent predictor of the composite end point of CV hospitalization, heart transplantation, and all-cause mortality [hazards ratio = 1.58; confidence interval, 95 (1.01-2.46); P = 0.045]. In conclusion, in patients in sinus rhythm with HFrEF submitted to CRT, DG use was associated with CV hospitalization, progression to heart transplant, and all-cause mortality.

Molecular detection of Papaya meleira virus in the latex of Carica papaya by RT-PCR.

A RT-PCR assay was developed for early and accurate detection of Papaya meleira virus (PMeV) in the latex from infected papayas. The meleira disease is characterized by an excessive exudation of more fluidic latex from fruits, leaves and stems. This latex oxidises and gives the fruit a "sticky" texture. In the field, disease symptoms are seen almost exclusively on fruit. However, infected plants can be a source of virus for dissemination by insects. Primers specific for PMeV were designed based on nucleotide sequences of the viral dsRNA obtained using a RT-RAPD approach. When tested for RT-PCR amplification, one of these primers (C05-3') amplified a 669-nucleotide fragment using dsRNA obtained from purified virus particles as a template. The translated sequence of this DNA fragment showed a certain degree of similarity to the amino acid sequence of RNA-dependent RNA polymerases from other dsRNA viruses. When used as the single primer in two RT-PCR kits available commercially, primer C05-3' also amplified the DNA fragment from papaya latex of infected, but not from healthy plants. The RT-PCR-based method developed in this study could simplify early plant disease diagnosis, assist in monitoring the dissemination of the pathogen within and between fields, and assist in guiding plant disease management.

Detection of Apple Stem Grooving Virus in Dormant Apple Trees with Crude Extracts as Templates for One-Step RT-PCR.

Partial nucleotide sequences of amplification products obtained from four European apple stem grooving virus (ASGV) isolates using degenerate primers showed 80 to 85% similarity with the published ASGV sequence of a Japanese strain but 98 to 100% identities among themselves. Based on these sequences, two ASGV-specific primers (ASGV4F-ASGV4R) were designed to amplify a 574-bp fragment located in the putative viral RNA polymerase. With these primers, six European and five American ASGV isolates, maintained in herbaceous hosts (Chenopodium quinoa, Nicotiana glutinosa, and N. occidentalis) or in apple trees, were readily detected by reverse transcription-polymerase chain reaction (RT-PCR). Using these specific ASGV primers, dsRNA preparations have been shown to constitute good templates for reliable amplification of ASGV sequences from leaves and bark tissues of apple trees, both in a two-step RT-PCR protocol and in the one-step Titan One-Tube RT-PCR. System. Furthermore, the one-step RT-PCR system allowed a specific amplification of ASGV sequences directly from clarified crude extracts of leaves and bark tissues of apple trees during both active growth and the dormant season.