Fibrilación auricular de novo y miocarditis aguda / De novo atrial fibrillation and acute myocarditis

Introducción: la miocarditis (MCT) se define como un infiltrado inflamatorio del miocardio con degeneración y/o necrosis asociada. Su etiología incluye múltiples gérmenes, tóxicos y enfermedades autoinmunes entre otros. La causa más común es la viral y el diagnóstico es un reto por la variabilidad de manifestaciones, imágenes y rendimiento del laboratorio. Objetivo:describir dos casos de miocarditis que debutaron con fibrilación auricular como manifestación poco usual. Metodología: se registraron dos casos en Cali, Colombia, con diagnóstico de miocarditis por resonancia magnética cardíaca (cRNM) contrastada. Presentación de los casos: el primero corresponde a una mujer de 66 años con antecedentes de diabetes e hipotiroidismo que ingresó por síncope y el segundo a un paciente joven con dolor torácico de 43 años sin antecedentes patológicos. Se documentó fibrilación auricular (FA) y MCT aguda por hallazgos en la cRNM. Se dió manejo médico y los pacientes evolucionaron en forma satisfactoria sin falla cardíaca en el seguimiento. Discusión y conclusiones: los casos ponen en evidencia la heterogeneidad de las manifestaciones clínicas de la MCT aguda y la importancia de sospecharla ante FA de novo. El diagnóstico puede retrasarse en nuestro medio por la falta de acceso a la cRNM, que se ha constituido como una herramienta fundamental para diferenciarla de otras etiologías que también elevan marcadores como la troponina ultrasensible y ponen en riesgo la vida del paciente como la isquemia miocárdica.

Introduction: myocarditis (MCT) is characterized by an inflammatory infiltration into the myocardium associated with degeneration and/or necrosis. Its etiologies include multiple bacteria, toxins, and autoimmune diseases among others. But most commonly it is induced by viruses. Diagnosis is challenging due to its variable presentation, imaging, and laboratory results. Objective: to describe two cases of myocarditis which debuted with atrial fibrillation as an unusual manifestation. Methodology: two cases were registered in Cali, Colombia, with myocarditis diagnosed by contrasted cardiovascular magnetic resonance imaging (cMRI). Cases: the first case corresponds to a 66-year-old female patient with a history of diabetes and hypothyroidism who was admitted for a syncope episode. The second case is a 43-year-old male with chest pain and a negative medical history. Atrial fibrillation (AF) and acute MCT were documented by cMRI. Patients received medical treatment and evolved satisfactorily presenting no cardiac failure at follow-up. Discussion and conclusions: these cases show the heterogeneity of acute MCT clinical manifestations and the importance of suspecting MCT in the presence of de novo AF. Diagnosis may be delayed in our setting due to the lack of access to cMRI, which has become a fundamental tool to distinguish MCT from other life-threatening conditions, such as myocardial ischemia, which also elevate markers such as ultrasensitive troponin

Molecular Testing of Serial Blood Specimens from Patients with Early Lyme Disease during Treatment Reveals Changing Coinfection with Mixtures of Borrelia burgdorferi Genotypes.

Borrelia burgdorferi is the etiological agent of Lyme disease. In the current study, we used direct-detection PCR and electrospray ionization mass spectrometry to monitor and genotype B. burgdorferi isolates from serially collected whole-blood specimens from patients clinically diagnosed with early Lyme disease before and during 21 days of antibiotic therapy. B. burgdorferi isolates were detected up to 3 weeks after the initiation of antibiotic treatment, with ratios of coinfecting B. burgdorferi genotypes changing over time.

Characterization of the Small RNA Transcriptome of the Marine Coccolithophorid, Emiliania huxleyi.

Small RNAs (smRNAs) control a variety of cellular processes by silencing target genes at the transcriptional or post-transcription level. While extensively studied in plants, relatively little is known about smRNAs and their targets in marine phytoplankton, such as Emiliania huxleyi (E. huxleyi). Deep sequencing was performed of smRNAs extracted at different time points as E. huxleyi cells transition from logarithmic to stationary phase growth in batch culture. Computational analyses predicted 18 E. huxleyi specific miRNAs. The 18 miRNA candidates and their precursors vary in length (18-24 nt and 71-252 nt, respectively), genome copy number (3-1,459), and the number of genes targeted (2-107). Stem-loop real time reverse transcriptase (RT) PCR was used to validate miRNA expression which varied by nearly three orders of magnitude when growth slows and cells enter stationary phase. Stem-loop RT PCR was also used to examine the expression profiles of miRNA in calcifying and non-calcifying cultures, and a small subset was found to be differentially expressed when nutrients become limiting and calcification is enhanced. In addition to miRNAs, endogenous small RNAs such as ra-siRNAs, ta-siRNAs, nat-siRNAs, and piwiRNAs were predicted along with the machinery for the biogenesis and processing of si-RNAs. This study is the first genome-wide investigation smRNAs pathways in E. huxleyi. Results provide new insights into the importance of smRNAs in regulating aspects of physiological growth and adaptation in marine phytoplankton and further challenge the notion that smRNAs evolved with multicellularity, expanding our perspective of these ancient regulatory pathways.