Estudio quimico preliminar de los fenoles y polifenoles de dos accesiones de calliandra calothyrsus (mimosaceae)

El objetivo de este estudio comparativo es conocer la composición química cualitativa y la concentración relativa de los fenoles y de los taninos condensados en dos accesiones de la especie forrajera Calliandra calothyrsus (Fabaceae Mimosaceae) cultivada y clasificada por el CIAT. El análisis por técnicas cromatográficas y métodos espectroscópicos permitió establecer claras diferencias en las dos muestras, no solo en cantidades sino en el número de derivados fenólicos observados. Entre los componentes fenólicos de bajo peso molecular identificados en las dos muestras sobresalen las isoflavonas: genisteína, prunetina y 7-O-glucosil-genisteína; catequinas, quercetina, miricetina y sus dihidroderivados, epigaloilcatequina, y galatos de epigaloilcatequinas. Entre los oligómeros, por MALDI-TOF y ESI en modo negativo se detectaron hasta pentámeros de catequinas en series de distintas combinaciones de monómeros según la regla Krueger

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality