Ancient plant DNA reveals High Arctic greening during the Last Interglacial.

Summer warming is driving a greening trend across the Arctic, with the potential for large-scale amplification of climate change due to vegetation-related feedbacks [Pearson et al., Nat. Clim. Chang. (3), 673-677 (2013)]. Because observational records are sparse and temporally limited, past episodes of Arctic warming can help elucidate the magnitude of vegetation response to temperature change. The Last Interglacial ([LIG], 129,000 to 116,000 y ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change [Otto-Bliesner et al., Philos. Trans. A Math. Phys. Eng. Sci. (371), 20130097 (2013) and Post et al., SciAdv (5), eaaw9883 (2019)]. However, high-latitude terrestrial records from this period are rare, so LIG vegetation distributions are incompletely known. Pollen-based vegetation reconstructions can be biased by long-distance pollen transport, further obscuring the paleoenvironmental record. Here, we present a LIG vegetation record based on ancient DNA in lake sediment and compare it with fossil pollen. Comprehensive plant community reconstructions through the last and current interglacial (the Holocene) on Baffin Island, Arctic Canada, reveal coherent climate-driven community shifts across both interglacials. Peak LIG warmth featured a ∼400-km northward range shift of dwarf birch, a key woody shrub that is again expanding northward. Greening of the High Arctic-documented here by multiple proxies-likely represented a strong positive feedback on high-latitude LIG warming. Authenticated ancient DNA from this lake sediment also extends the useful preservation window for the technique and highlights the utility of combining traditional and molecular approaches for gleaning paleoenvironmental insights to better anticipate a warmer future.

Telemedicine consultation for emergency patients' attention: a clinical experience from a high complex university hospital from Latin America.

INTRODUCTION: As a result of the new coronavirus pandemic, a highly complex academic hospital in Latin America implemented a telemedicine service for the care of obstetric, pediatric, and adult patients. In 2020, regional emergency services collapsed due to the increase in demand for care, generating the need to open expansion services and seek strategies to provide timely care to consulting patients. OBJECTIVE: We retrospectively describe the clinical experience of patients who consulted the emergency department via telemedicine across a videoconference tool using digital platforms. METHODS: A descriptive study with retrospective data collection was conducted to describe the implementation of the teleconsultation care model for patients. We constructed the clinical process indicators to evaluate the model. RESULTS: A total of 4652 teleconsultations were registered. Telemedicine consultation was above 50% in the country and department and above 90% in Cali city. The average waiting time for care was estimated to be 1:59:52 h. A total of 275 patients were transferred to the emergency room after consultation. The principal reasons for consultation in the institutional telemedicine program were respiratory and gastrointestinal symptoms. Teleconsultations related to SARS-COV 2 infections reported 3775 patients (3127 with unidentified virus and 648 with the identified virus). CONCLUSIONS: Telemedicine is a tool that provides support and guidance to patients who consult emergency departments, reducing barriers to access health care and decreasing emergency department collapse.

Arctic shrub colonization lagged peak postglacial warmth: Molecular evidence in lake sediment from Arctic Canada.

Arctic shrubification is an observable consequence of climate change, already resulting in ecological shifts and global-scale climate feedbacks including changes in land surface albedo and enhanced evapotranspiration. However, the rate at which shrubs can colonize previously glaciated terrain in a warming world is largely unknown. Reconstructions of past vegetation dynamics in conjunction with climate records can provide critical insights into shrubification rates and controls on plant migration, but paleoenvironmental reconstructions based on pollen may be biased by the influx of exotic pollen to tundra settings. Here, we reconstruct past plant communities using sedimentary ancient DNA (sedaDNA), which has a more local source area than pollen. We additionally reconstruct past temperature variability using bacterial cell membrane lipids (branched glycerol dialkyl glycerol tetraethers) and an aquatic productivity indicator (biogenic silica) to evaluate the relative timing of postglacial ecological and climate changes at a lake on southern Baffin Island, Arctic Canada. The sedaDNA record tightly constrains the colonization of dwarf birch (Betula, a thermophilous shrub) to 5.9 ± 0.1 ka, ~3 ka after local deglaciation as determined by cosmogenic 10 Be moraine dating and >2 ka later than Betula pollen is recorded in nearby lake sediment. We then assess the paleovegetation history within the context of summer temperature and find that paleotemperatures were highest prior to 6.3 ka, followed by cooling in the centuries preceding Betula establishment. Together, these molecular proxies reveal that Betula colonization lagged peak summer temperatures, suggesting that inefficient dispersal, rather than climate, may have limited Arctic shrub migration in this region. In addition, these data suggest that pollen-based climate reconstructions from high latitudes, which rely heavily on the presence and abundance of pollen from thermophilous taxa like Betula, can be compromised by both exotic pollen fluxes and vegetation migration lags.

Immunohistochemical analysis of paraoxonases and chemokines in arteries of patients with peripheral artery disease.

Oxidative damage to lipids and lipoproteins is implicated in the development of atherosclerotic vascular diseases, including peripheral artery disease (PAD). The paraoxonases (PON) are a group of antioxidant enzymes, termed PON1, PON2, and PON3 that protect lipoproteins and cells from peroxidation and, as such, may be involved in protection against the atherosclerosis process. PON1 inhibits the production of chemokine (C-C motif) ligand 2 (CCL2) in endothelial cells incubated with oxidized lipoproteins. PON1 and CCL2 are ubiquitously distributed in tissues, and this suggests a joint localization and combined systemic effect. The aim of the present study has been to analyze the quantitative immunohistochemical localization of PON1, PON3, CCL2 and CCL2 receptors in a series of patients with severe PAD. Portions of femoral and/or popliteal arteries from 66 patients with PAD were obtained during surgical procedures for infra-inguinal limb revascularization. We used eight normal arteries from donors as controls. PON1 and PON3, CCL2 and the chemokine-binding protein 2, and Duffy antigen/chemokine receptor, were increased in PAD patients. There were no significant changes in C-C chemokine receptor type 2. Our findings suggest that paraoxonases and chemokines play an important role in the development and progression of atherosclerosis in peripheral artery disease.

Understanding the role of circulating chemokine (C-C motif) ligand 2 in patients with chronic ischemia threatening the lower extremities.

The role of chemokine (C-C motif) ligand 2 (CCL2) in peripheral artery disease is unclear. We measured the difference between serum and plasma levels of CCL2 in patients with chronic ischemia threatening the lower extremities following the observation that atypical chemokine receptors in blood and tissue cells may prevent CCL2 from entering the circulation and consequently modulate its function of attracting monocytes to the site of lesion. To identify the influence of CCL2, we compared the patients' values to those in bio-banked samples from a control population. Further, we explored the association with the Asp42Gly polymorphism (rs12075) in Duffy antigen chemokine receptor; one of these atypical chemokine receptors. When possible, we evaluated in surgically excised normal and affected arteries the calcium burden as well as the expression of CCL2 and related receptors reflecting the inflammatory status. Our findings indicate that circulating CCL2 was significantly associated with the severity and presence of the disease (OR 0.966, 95% CI 0.944 to 0.988, p = 0.003). Circulating CCL2 was dependent on the rs12075 genotype (AA>AG>GG), which, probably, indicates a higher expression of chemokine receptor in the arteries of AA subjects. The associations with genetic variants and the over-expression of atypical chemokine receptors in diseased arteries may have potential implications and our data indicate that CCL2 may represent a previously unrecognized factor that needs to be considered in the screening of patients with risk factors for peripheral artery disease.

Principal causes of acute poisoning in an emergency service: experience between 2014 and 2021 at a University Hospital in Southwestern Colombia.

Acute poisonings are a global public health problem, which implies costs and disease burden for society. In Colombia, there is a significant underreporting of data on acute poisoning and data gaps on the toxicological profile of the population. This study aims to identify the epidemiology of acute poisoning in a high-complexity hospital in southwestern Colombia. A descriptive study with retrospective data collection was performed. The variables were expressed through the measure of central tendency and dispersion. Categorical variables were described in proportions. A total of 406 patients were included. The median age was 31 years (IQR 23-48), 56.2% were male, and only 19.2% had a history of mental illness. Suicidal intent represented 58.8% of the cases, and the most frequent route of exposure was the oral route (81.6%). The most prevalent groups of substances were pesticides (34.2%) and medicines (32%). The most common etiological agent was organophosphates (16.5%). Cholinergic toxidrome was the most common. The average stay in the ICU was 4.5 days (± 4.8), and the mortality was 4.2%. The principal causes of acute poisoning were drugs and pesticides, with a predominant etiology of organophosphates and depressants of the central nervous system. There was a significant predominance of young male patients with suicidal intent, low mental disorders, elevated unemployment rate, and similar mortality reported in other studies. This study improves the knowledge about acute poisoning in southwestern Colombian to carry out multicenter analytic studies.

Electrocardiographic Abnormalities in Patients with Hyperkalemia: A Retrospective Study in an Emergency Department in Colombia.

Introduction: Hyperkalemia is a prevalent electrolyte disorder related to elevated serum potassium levels, resulting in diverse abnormal electrocardiographic findings and associated clinical signs and symptoms, often necessitating specific treatment. However, in some patients, these abnormal findings may not be present on the electrocardiogram even in elevated serum potassium levels. This study aims to identify electrocardiographic abnormalities related to the severity of hyperkalemia and the clinical outcomes in an emergency department in southwestern Colombia. Methodology: This is a retrospective cross-sectional descriptive study. We described the electrocardiographic findings, clinical characteristics, treatment, and outcomes related to the degrees of hyperkalemia. The potential association between the severity of hyperkalemia and electrocardiographic findings was evaluated. Results: A total of 494 patients were included. The median of the potassium level was 6.6 mEq/L. Abnormal electrocardiographic findings were reported in 61.5% of the cases. Mild and severe hyperkalemia groups reported abnormalities in 59.9% and 61.2%, respectively. The most common electrocardiography abnormalities were the peaked T wave 36.2%, followed by wide QRS 83 (16.8%). Only 1.4% of patients had adverse outcomes. The abnormal findings were registered in 61.5%. Mortality was 11.9%. The peaked T wave was the most common finding across different levels of hyperkalemia severity. Conclusion: High serum potassium levels are related with abnormal ECG. However, patients with different degrees of hyperkalemia could not describe abnormal ECG findings. In a high proportion of patients with renal chronic disease and hyperkalemia, the abnormalities in the ECG could be minimal or absent.

Intact polar lipidome and membrane adaptations of microbial communities inhabiting serpentinite-hosted fluids.

The generation of hydrogen and reduced carbon compounds during serpentinization provides sustained energy for microorganisms on Earth, and possibly on other extraterrestrial bodies (e.g., Mars, icy satellites). However, the geochemical conditions that arise from water-rock reaction also challenge the known limits of microbial physiology, such as hyperalkaline pH, limited electron acceptors and inorganic carbon. Because cell membranes act as a primary barrier between a cell and its environment, lipids are a vital component in microbial acclimation to challenging physicochemical conditions. To probe the diversity of cell membrane lipids produced in serpentinizing settings and identify membrane adaptations to this environment, we conducted the first comprehensive intact polar lipid (IPL) biomarker survey of microbial communities inhabiting the subsurface at a terrestrial site of serpentinization. We used an expansive, custom environmental lipid database that expands the application of targeted and untargeted lipodomics in the study of microbial and biogeochemical processes. IPLs extracted from serpentinite-hosted fluid communities were comprised of >90% isoprenoidal and non-isoprenoidal diether glycolipids likely produced by archaeal methanogens and sulfate-reducing bacteria. Phospholipids only constituted ~1% of the intact polar lipidome. In addition to abundant diether glycolipids, betaine and trimethylated-ornithine aminolipids and glycosphingolipids were also detected, indicating pervasive membrane modifications in response to phosphate limitation. The carbon oxidation state of IPL backbones was positively correlated with the reduction potential of fluids, which may signify an energy conservation strategy for lipid synthesis. Together, these data suggest microorganisms inhabiting serpentinites possess a unique combination of membrane adaptations that allow for their survival in polyextreme environments. The persistence of IPLs in fluids beyond the presence of their source organisms, as indicated by 16S rRNA genes and transcripts, is promising for the detection of extinct life in serpentinizing settings through lipid biomarker signatures. These data contribute new insights into the complexity of lipid structures generated in actively serpentinizing environments and provide valuable context to aid in the reconstruction of past microbial activity from fossil lipid records of terrestrial serpentinites and the search for biosignatures elsewhere in our solar system.

Delayed postglacial colonization of Betula in Iceland and the circum North Atlantic.

As the Arctic continues to warm, woody shrubs are expected to expand northward. This process, known as 'shrubification,' has important implications for regional biodiversity, food web structure, and high-latitude temperature amplification. While the future rate of shrubification remains poorly constrained, past records of plant immigration to newly deglaciated landscapes in the Arctic may serve as useful analogs. We provide one new postglacial Holocene sedimentary ancient DNA (sedaDNA) record of vascular plants from Iceland and place a second Iceland postglacial sedaDNA record on an improved geochronology; both show Salicaceae present shortly after deglaciation, whereas Betulaceae first appears more than 1000 y later. We find a similar pattern of delayed Betulaceae colonization in eight previously published postglacial sedaDNA records from across the glaciated circum North Atlantic. In nearly all cases, we find that Salicaceae colonizes earlier than Betulaceae and that Betulaceae colonization is increasingly delayed for locations farther from glacial-age woody plant refugia. These trends in Salicaceae and Betulaceae colonization are consistent with the plant families' environmental tolerances, species diversity, reproductive strategies, seed sizes, and soil preferences. As these reconstructions capture the efficiency of postglacial vascular plant migration during a past period of high-latitude warming, a similarly slow response of some woody shrubs to current warming in glaciated regions, and possibly non-glaciated tundra, may delay Arctic shrubification and future changes in the structure of tundra ecosystems and temperature amplification.

Phytoplankton response to a warming ocean.

The nutritional value of marine algae will decrease in a warmer world.

Near-universal trends in brGDGT lipid distributions in nature.

Bacterial brGDGT lipids are a prevalent tool in studies of terrestrial paleoclimate. Their distributions correlate empirically with environmental temperature and pH, and their ubiquity in terrestrial, freshwater, and marine environments gives them wide applicability. Whether correlations with temperature and pH emerge due to a physiological response of source organisms and/or a shift in bacterial community composition remains an open question with important implications for proxy development and application. We applied a newly described technique for grouping brGDGTs to a globally compiled dataset (n = 3129) consisting of all modern sample media known to host brGDGTs. We found strong resemblances in the relationships between brGDGT fractional abundances and both temperature and pH across nearly all sample types examined. We also found near-universal connections between the brGDGTs themselves. Given the markedly different bacterial communities expected to inhabit these settings, these widespread relationships may suggest physiological and/or biochemical bases for observed brGDGT distributions.

Bacterial and archaeal lipids trace chemo(auto)trophy along the redoxcline in Vancouver Island fjords.

Marine oxygen minimum zones play a crucial role in the global oceanic carbon, nitrogen, and sulfur cycles as they harbor microbial communities that are adapted to the water column chemistry and redox zonation, and in turn control the water column chemistry and greenhouse gas release. These micro-organisms have metabolisms that rely on terminal electron acceptors other than O2 and often benefit from syntrophic relationships (metabolic coupling). Here, we study chemo(auto)trophy along the redoxcline in two stratified fjords on Vancouver Island (Canada) using bacterial bacteriohopanepolyols and archaeal ether lipids. We analyze the distribution of these lipid classes in suspended particulate matter (SPM) to trace ammonia oxidation, anaerobic ammonium oxidation (anammox), sulfate reduction/sulfur oxidation, methanogenesis, and methane oxidation, and investigate ecological niches to evaluate potential links between their respective bacterial and archaeal sources. Our results show an unparalleled BHP and ether lipid structural diversity that allows tracing the major redox-driven metabolic processes at the time of sampling: Both fjords are dominated by archaeal ammonia oxidation and anammox; sulfate-reducing bacteria may be present in Deer Bay, but absent from Effingham Inlet; methanogenic Euryarchaeota and archaeal and bacterial methanotrophs are detectable at low abundance. Correlation analysis reveals distinct biomarker clusters that provide constraints on the biogeochemical niches of some orphan BHP and ether lipids such as in situ-produced adenosyl-BHPs or unsaturated archaeols.

A source of isotopically light organic carbon in a low-pH anoxic marine zone.

Geochemical and stable isotope measurements in the anoxic marine zone (AMZ) off northern Chile during periods of contrasting oceanographic conditions indicate that microbial processes mediating sulfur and nitrogen cycling exert a significant control on the carbonate chemistry (pH, AT, DIC and pCO2) of this region. Here we show that in 2015, a large isotopic fractionation between DIC and POC, a DIC and N deficit in AMZ waters indicate the predominance of in situ dark carbon fixation by sulfur-driven autotrophic denitrification in addition to anammox. In 2018, however, the fractionation between DIC and POC was significantly lower, while the total alkalinity increased in the low-pH AMZ core, suggesting a predominance of heterotrophic processes. An isotope mass-balance model demonstrates that variations in the rates of sulfur- and nitrogen-mediated carbon fixation in AMZ waters contribute ~7-35% of the POC exported to deeper waters. Thus, dark carbon fixation should be included in assessments of future changes in carbon cycling and carbonate chemistry due to AMZ expansion.

An 80-Year-Old Woman with Alzheimer Disease and Accidental Poisoning with Pyrethroid Pesticide Successfully Treated with Intravenous Lipid Emulsion.

BACKGROUND Pesticides are commonly used in the agricultural industry. Overdose can be lethal due to its effects generating closure of the voltage-gated sodium channels in the axonal membranes. Most case reports of toxicity refer to skin exposure and there are very few that refer to effects due to its oral intake. CASE REPORT We report the case of an elderly woman with Alzheimer disease who accidentally swallowed 50 g of Lambda Cyhalothrin (GOLPE 5 M E®), a pyrethroid of medium toxicity containing a cyano group. It severely harmed the woman's health, causing severe central nervous system depression and refractory vasodilated shock requiring the use of vasopressors. Its management was challenging, requiring orotracheal intubation, vasopressors, and admission to the Intensive Care Unit (ICU). The emergency care team decided to use intravenous lipid emulsion, which clearly helped with the recovery and successful discharge of the patient. CONCLUSIONS The use of intravenous lipid emulsion for the treatment of pyrethroid poisoning can lead to successful outcomes, as described in this case report.

On impact and volcanism across the Cretaceous-Paleogene boundary.

The cause of the end-Cretaceous mass extinction is vigorously debated, owing to the occurrence of a very large bolide impact and flood basalt volcanism near the boundary. Disentangling their relative importance is complicated by uncertainty regarding kill mechanisms and the relative timing of volcanogenic outgassing, impact, and extinction. We used carbon cycle modeling and paleotemperature records to constrain the timing of volcanogenic outgassing. We found support for major outgassing beginning and ending distinctly before the impact, with only the impact coinciding with mass extinction and biologically amplified carbon cycle change. Our models show that these extinction-related carbon cycle changes would have allowed the ocean to absorb massive amounts of carbon dioxide, thus limiting the global warming otherwise expected from postextinction volcanism.

Biochemical indices of oxidative stress and inflammation in the evaluation of peripheral artery disease.

BACKGROUND: The aims of this study were: (1) to investigate changes in indices of oxidative stress and inflammation in the evaluation of peripheral artery disease (PAD); (2) to compare the diagnostic efficacy of these parameters with that of classical clinical laboratory routine parameters. DESIGN AND METHODS: We studied 115 patients with PAD and 300 healthy volunteers. RESULTS: PAD patients had significantly increased circulating concentrations of F2-isoprostanes, protein carbonyls, chemokine (C-C motif) ligand 2 (CCL2), high-sensitivity C-reactive protein (hs-CRP), ß-2-microglobulin (B2M), and decreased paraoxonase-1 (PON1) levels. When patients were classified according to the Fontaine score, we observed important increases in plasma F2-isoprostanes and CCL2 that appeared in milder stages of the disease, and remained so at similar levels in more advanced stages; almost no overlapping with the control group was noted. Receiver operating characteristics analysis comparing patients and controls revealed that the areas under the curve for F2-isoprostanes and CCL2 approached unity [0.999 (0.998-1.000) and 0.993 (0.985-1.000)], respectively, and significantly higher to those of the other measured parameters. CONCLUSION: Our data suggest that F2-isoprostanes and CCL2 measurements may be useful tools for the diagnosis of PAD.

Posterior bladder layering of excreted 18F-FDG on PET/CT.

PURPOSE: This study was carried out to determine the frequency, characteristics and possible causes and clinical significance of occasionally observed posterior layering of excreted 2-deoxy-2-[F]fluoro-D-glucose (F-FDG) in the bladder. PROCEDURES: A review of 567 consecutive patients referred for positron emission tomography/computerized tomography studies was performed. Urinary bladder size was measured in patients with and without layering. Urine samples from two patients with layering were imaged ex vivo. RESULTS: Twenty-four of 567 studies (4%) showed F-FDG posterior bladder layering. Mean volume+/-SD of the bladder was 175+/-161 ml in patients with layering and 93+/-83 ml in patients without layering. Urine samples collected from two randomly chosen patients with layering in vivo failed to show layering ex vivo. CONCLUSION: Posterior F-FDG layering occurs in 4% of positron emission tomography/computerized tomography cases and highly correlates with bladder volume. The mechanism is hypothesized to be because of slow F-FDG excretion in patients with a distended urinary bladder resulting in delayed mixing with urine, but needs to be further investigated with a more comprehensive study.

Rapid resurgence of marine productivity after the Cretaceous-Paleogene mass extinction.

The course of the biotic recovery after the impact-related disruption of photosynthesis and mass extinction event at the Cretaceous-Paleogene boundary has been intensely debated. The resurgence of marine primary production in the aftermath remains poorly constrained because of the paucity of fossil records tracing primary producers that lack skeletons. Here we present a high-resolution record of geochemical variation in the remarkably thick Fiskeler (also known as the Fish Clay) boundary layer at Kulstirenden, Denmark. Converging evidence from the stable isotopes of carbon and nitrogen and abundances of algal steranes and bacterial hopanes indicates that algal primary productivity was strongly reduced for only a brief period of possibly less than a century after the impact, followed by a rapid resurgence of carbon fixation and ecological reorganization.

Initial experience with the radiotracer anti-1-amino-3-[18F]Fluorocyclobutane-1-carboxylic acid (anti-[ 18F]FACBC) with PET in renal carcinoma.

PURPOSE: Assessment of renal masses with conventional imaging may be challenging. Anti-1-amino-3-[(18)F]fluorocyclobutane-1-carboxylic acid (anti-[18F]FACBC) is a synthetic L: -leucine analog with relatively little renal excretion. The present study examines anti-[(18)F]FACBC positron emission tomography uptake in patients with renal masses. PROCEDURES: Six patients with seven renal lesions were imaged dynamically for 2 h after injection of 10-10.9 mCi (370-403 MBq) anti-[(18)F]FACBC. Lesions were evaluated qualitatively and quantitatively and correlated with histology. RESULTS: Four clear cell and one Rosai-Dorfman lesion were hypo/isointense to normal cortex; two papillary lesions in the same patient were hyperintense. Mean SUV(max) +/- SD at 30 min was 2.8 +/- 0.24 for clear cell carcinomas and 4.5 +/- 1.7 for papillary cell lesions. Mean SUV(max)/SUV(mean) ratios +/- SD of lesion to normal cortex at 30 min was 1.15 +/- 0.19 for the clear cell carcinomas and 2.3 +/- 0.84 for papillary cell. CONCLUSIONS: In this small patient sample, relative amino acid transport compared with renal cortex is elevated in renal papillary cell carcinoma but not in clear cell carcinoma.