Timing the evolution of phosphorus-cycling enzymes through geological time using phylogenomics

Phosphorus plays a crucial role in controlling biological productivity, but geological estimates of phosphate concentrations in the Precambrian ocean, during life’s origin and early evolution, vary over several orders of magnitude. While reduced phosphorus species may have served as alternative substrates to phosphate, their bioavailability on the early Earth remains unknown. Here, we reconstruct the phylogenomic record of life on Earth and find that phosphate transporting genes (pnas) evolved in the Paleoarchean (ca. 3.6-3.2 Ga) and are consistent with phosphate concentrations above modern levels ( > 3 µM). The first gene optimized for low phosphate levels (pstS; <1 µM) appeared around the same time or in the Mesoarchean depending on the reconstruction method. Most enzymatic pathways for metabolising reduced phosphorus emerged and expanded across the tree of life later. This includes phosphonate-catabolising CP-lyases, phosphite-oxidising pathways and hypophosphite-oxidising pathways. CP-lyases are particularly abundant in dissolved phosphate concentrations below 0.1 µM. Our results thus indicate at least local regions of declining phosphate levels through the Archean, possibly linked to phosphate-scavenging Fe(III), which may have limited productivity. However, reduced phosphorus species did not become widely used until after the Paleoproterozoic Great Oxidation Event (2.3 Ga), possibly linked to expansion of the biosphere at that time.Peer reviewe

Timing the evolution of antioxidant enzymes in cyanobacteria

How early photosynthesizers managed oxidative stress remains relatively unresolved. Analyses of enzymes dealing with reactive oxygen species traces the evolutionary history of superoxide dismutases and finds evidence of CuZnSOD in the ancestor of all cyanobacteria, dating back to the Archaean

The evolution and spread of sulfur cycling enzymes reflect the redox state of the early Earth

Funding: K.M. was supported by the Dean of the College Office at Carleton College. This work was performed by the Virtual Planetary Laboratory team, a member of the NASA Nexus for Exoplanet System Science, funded via NASA Astrobiology Program grant no. 80NSSC18K0829 to R.A. Financial support for this publication also results from a Scialog program sponsored jointly by Research Corporation for Science Advancement and the Heising-Simons Foundation and includes a grant (no. 28109) to Carleton College by RCSA. E.S. and J.B. acknowledge funding from a NERC Frontiers grant (NE/V010824/1).The biogeochemical sulfur cycle plays a central role in fueling microbial metabolisms, regulating the Earth's redox state, and affecting climate. However, geochemical reconstructions of the ancient sulfur cycle are confounded by ambiguous isotopic signals. We use phylogenetic reconciliation to ascertain the timing of ancient sulfur cycling gene events across the tree of life. Our results suggest that metabolisms using sulfide oxidation emerged in the Archean, but those involving thiosulfate emerged only after the Great Oxidation Event. Our data reveal that observed geochemical signatures resulted not from the expansion of a single type of organism but were instead associated with genomic innovation across the biosphere. Moreover, our results provide the first indication of organic sulfur cycling from the Mid-Proterozoic onwards, with implications for climate regulation and atmospheric biosignatures. Overall, our results provide insights into how the biological sulfur cycle evolved in tandem with the redox state of the early Earth.Publisher PDFPeer reviewe

Evolution in Cardiovascular Care for Elderly Patients With Non–ST-Segment Elevation Acute Coronary Syndromes: Results From the CRUSADE National Quality Improvement Initiative

OBJECTIVES This study evaluated the impact of age on care and outcomes for non-ST-segment elevation acute coronary syndromes (NSTE ACS). BACKGROUND Recent clinical trials have expanded treatment options for NSTE ACS, now reflected in guidelines. Elderly patients are at highest risk, yet have previously been shown to receive less care than younger patients. METHODS In 56,963 patients with NSTE ACS at 443 U.S. hospitals participating in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) National Quality Improvement Initiative from January 2001 to June 2003, we compared use of guidelines-recommended care across four age groups: <65, 65 to 74, 75 to 84, and ≥85 years. A multivariate model tested for age-related differences in treatments and outcomes after adjusting for patient, provider, and hospital factors. RESULTS Of the study population, 35% were ≥75 years old, and 11% were ≥85 years old. Use of acute anti-platelet and anti-thrombin therapy within the first 24 h decreased with age. Elderly patients were also less likely to undergo early catheterization or revascularization. Whereas use of many discharge medications was similar in young and old patients, clopidogrel and lipid-lowering therapy remained less commonly prescribed in elderly patients. In-hospital mortality and complication rates increased with advancing age, but those receiving more recommended therapies had lower mortality even after adjustment than those who did not. CONCLUSIONS Age impacts use of guidelines-recommended care for newer agents and early in-hospital care. Further improvements in outcomes for elderly patients by optimizing the safe and early use of therapies are likely

Identificaction and quantificationof proteins from Methylophaga Thiooxidans and Methylocella Silvestris using label-free LC/MS

Comunicaciones a congreso

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011