Contenido de prolina en Solanum lycopersicum pretratado con glicina betaina y sometido a estrés salino

Las plantas han desarrollado varios mecanismos protectores para contrarrestar el estrés salino, uno de ellos es la acumulación de solutos compatibles como prolina y glicina betaina. Sin embargo, algunos cultivos como el tomate no acumulan glicina betaina, ante esto surge la alternativa de la aplicación exógena de estos compuestos. En este trabajo, se propuso evaluar el contenido de prolina en relación al estado hídrico en plántulas de Solanum lycopersicum  var. Río Grande “tomate” pretratado con diferentes concentraciones de glicina betaina y cultivadas en diferentes niveles de salinidad.  Plántulas fueron tratadas con glicina betaina a concentraciones de 0, 1 y 10 mM, y luego sometidas a cloruro de sodio: 0, 100 y 200 mM agregada esta sal a la solución de riego. Después de 10 días de tratamiento se cuantificó prolina y contenido relativo de agua. El contenido de prolina aumentó con el grado de salinidad y la aplicación de Glicina betaina 1 mM produjo un aumento significativo en NaCl 100mM.Palabras clave: prolina, glicina betaina, estrés salino, Solanu

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A worldwide perspective of sepsis epidemiology and survival according to age: Observational data from the ICON audit

Purpose: To investigate age-related differences in outcomes of critically ill patients with sepsis around the world. Methods: We performed a secondary analysis of data from the prospective ICON audit, in which all adult ( >16 years ) patients admitted to participating ICUs between May 8 and 18, 2012, were included, except admissions for routine postoperative observation. For this sub-analysis, the 10,012 patients with completed age data were included. They were divided into five age groups - <= 50, 51-60, 61-70, 71-80, >80 years. Sepsis was defined as infection plus at least one organ failure. Results: A total of 2963 patients had sepsis, with similar proportions across the age groups (<= 50 = 25.2%: 51-60 = 30.3%; 61-70 = 32.8%; 71-80 = 30.7%; >80 = 30.9%). Hospital mortality increased with age and in patients >80 years was almost twice that of patients <= 50 years (493% vs 25.2%, p < .05). The maximum rate of increase in mortality was about 0.75% per year, occurring between the ages of 71 and 77 years. In multilevel analysis, age > 70 years was independently associated with increased risk of dying. Conclusions: The odds for death in ICU patients with sepsis increased with age with the maximal rate of increase occurring between the ages of 71 and 77 years. (C) 2019 Elsevier Inc. All rights reserved