Multimodal single-cell datasets characterize antigen-specific CD8+ T cells across SARS-CoV-2 vaccination and infection.

The immune response to SARS-CoV-2 antigen after infection or vaccination is defined by the durable production of antibodies and T cells. Population-based monitoring typically focuses on antibody titer, but there is a need for improved characterization and quantification of T cell responses. Here, we used multimodal sequencing technologies to perform a longitudinal analysis of circulating human leukocytes collected before and after immunization with the mRNA vaccine BNT162b2. Our data indicated distinct subpopulations of CD8+ T cells, which reliably appeared 28 days after prime vaccination. Using a suite of cross-modality integration tools, we defined their transcriptome, accessible chromatin landscape and immunophenotype, and we identified unique biomarkers within each modality. We further showed that this vaccine-induced population was SARS-CoV-2 antigen-specific and capable of rapid clonal expansion. Moreover, we identified these CD8+ T cell populations in scRNA-seq datasets from COVID-19 patients and found that their relative frequency and differentiation outcomes were predictive of subsequent clinical outcomes.

Reintroducing bison results in long-running and resilient increases in grassland diversity.

The widespread extirpation of megafauna may have destabilized ecosystems and altered biodiversity globally. Most megafauna extinctions occurred before the modern record, leaving it unclear how their loss impacts current biodiversity. We report the long-term effects of reintroducing plains bison (Bison bison) in a tallgrass prairie versus two land uses that commonly occur in many North American grasslands: 1) no grazing and 2) intensive growing-season grazing by domesticated cattle (Bos taurus). Compared to ungrazed areas, reintroducing bison increased native plant species richness by 103% at local scales (10 m2) and 86% at the catchment scale. Gains in richness continued for 29 y and were resilient to the most extreme drought in four decades. These gains are now among the largest recorded increases in species richness due to grazing in grasslands globally. Grazing by domestic cattle also increased native plant species richness, but by less than half as much as bison. This study indicates that some ecosystems maintain a latent potential for increased native plant species richness following the reintroduction of native herbivores, which was unmatched by domesticated grazers. Native-grazer gains in richness were resilient to an extreme drought, a pressure likely to become more common under future global environmental change.

Cardiogenic Shock Intravascular Cooling Trial (CHILL-SHOCK).

BACKGROUND: Cardiogenic shock (CS) is complicated by high mortality rates. Targeted temperature control (TTC) has been proposed as an adjunct therapy in CS. This study aims to examine the safety of TTC in patients presenting with CS. METHODS AND RESULTS: In this open-label, randomized controlled pilot trial, 20 patients with hemodynamic criteria for CS were assigned to standard of care plus TTC vs standard of care alone. The primary outcome was a composite safety outcome, including well-described complications of TTC. Secondary outcomes included mortality at 90 days, invasive hemodynamic and echocardiographic parameters, electrocardiographic measurements, and inotrope dosing. There were no significant differences in the composite analysis of prespecified safety outcomes (3 events in the TTC group vs 0 events in the control group; P = 0.24). Patients randomized to TTC demonstrated a statistically significant increase in cardiac index and cardiac power index compared to the control group at 48-96 hours after randomization (3.6 [3.1, 3.9] L/min/m2 vs 2.6 [2.5, 3.15] L/min/m2; P = 0.029 and 0.61 [0.55, 0.7] W/m2 vs 0.53 [0.435, 0.565] W/m2; P = 0.029, respectively). CONCLUSION: TTC may be a safe adjunct therapy for patients presenting with CS and may yield improvement in specific hemodynamic parameters.

An exploration of the experiences and self-generated strategies used when navigating everyday life with Long Covid.

BACKGROUND: Around one in ten people who contract Covid-19 report ongoing symptoms or 'Long Covid'. Without any known interventions to cure the condition, forms of self-management are routinely prescribed by healthcare professionals and described by people with the condition. However, there is limited research exploring what strategies are used to navigate everyday life with Long Covid, and experiences that initiate development of these strategies. Our study aimed to explore the range and influence of self-generated strategies used by people with Long Covid to navigate everyday life within the context of their own condition. METHODS: Forming part of the Long Covid Personalised Self-managemenT support co-design and EvaluatioN (LISTEN) project, we conducted a qualitative study using narrative interviews with adults who were not hospitalised with Covid-19. Participants aged over 18 years, who self-identified with Long Covid, were recruited from England and Wales. Data were analysed with patient contributors using a reflexive thematic analysis. RESULTS: Eighteen participants (mean age = 44 years, SD = 13 years) took part in interviews held between December 2021 and February 2022. Themes were constructed which depicted 1) the landscape behind the Long Covid experience and 2) the everyday experience of participants' Long Covid. The everyday experience comprised a combination of physical, emotional, and social factors, forming three sub-themes: centrality of physical symptoms, navigating 'experts' and the 'true colour' of personal communities, and a rollercoaster of psychological ambiguity). The third theme, personal strategies to manage everyday life was constructed from participants' unique presentations and self-generated solutions to manage everyday life. This comprised five sub-themes: seeking reassurance and knowledge, developing greater self-awareness through monitoring, trial and error of 'safe' ideas, building in pleasure and comfort, and prioritising 'me'. CONCLUSIONS: Among this sample of adults with Long Covid, their experiences highlighted the unpredictable nature of the condition but also the use of creative and wide ranging self-generated strategies. The results offer people with Long Covid, and healthcare professionals supporting them, an overview of the collective evidence relating to individuals' self-management which can enable ways to live 'better' and regain some sense of identity whilst facing the impact of a debilitating, episodic condition. TRIAL REGISTRATION: LISTEN ISRCTN36407216.

Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure.

BACKGROUND: In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit. METHODS: REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization. RESULTS: Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P=0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P=0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P=0.004). CONCLUSIONS: In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.

Multiple global change drivers show independent, not interactive effects: a long-term case study in tallgrass prairie.

Ecosystems are faced with an onslaught of co-occurring global change drivers. While frequently studied independently, the effects of multiple global change drivers have the potential to be additive, antagonistic, or synergistic. Global warming, for example, may intensify the effects of more variable precipitation regimes with warmer temperatures increasing evapotranspiration and thereby amplifying the effect of already dry soils. Here, we present the long-term effects (11 years) of altered precipitation patterns (increased intra-annual variability in the growing season) and warming (1 °C year-round) on plant community composition and aboveground net primary productivity (ANPP), a key measure of ecosystem functioning in mesic tallgrass prairie. Based on past results, we expected that increased precipitation variability and warming would have additive effects on both community composition and ANPP. Increased precipitation variability altered plant community composition and increased richness, with no effect on ANPP. In contrast, warming decreased ANPP via reduction in grass stems and biomass but had no effect on the plant community. Contrary to expectations, across all measured variables, precipitation and warming treatments had no interactive effects. While treatment interactions did not occur, each treatment did individually impact a different component of the ecosystem (i.e., community vs. function). Thus, different aspects of the ecosystem may be sensitive to different global change drivers in mesic grassland ecosystems.

Climate legacies determine grassland responses to future rainfall regimes.

Climate variability and periodic droughts have complex effects on carbon (C) fluxes, with uncertain implications for ecosystem C balance under a changing climate. Responses to climate change can be modulated by persistent effects of climate history on plant communities, soil microbial activity, and nutrient cycling (i.e., legacies). To assess how legacies of past precipitation regimes influence tallgrass prairie C cycling under new precipitation regimes, we modified a long-term irrigation experiment that simulated a wetter climate for >25 years. We reversed irrigated and control (ambient precipitation) treatments in some plots and imposed an experimental drought in plots with a history of irrigation or ambient precipitation to assess how climate legacies affect aboveground net primary productivity (ANPP), soil respiration, and selected soil C pools. Legacy effects of elevated precipitation (irrigation) included higher C fluxes and altered labile soil C pools, and in some cases altered sensitivity to new climate treatments. Indeed, decades of irrigation reduced the sensitivity of both ANPP and soil respiration to drought compared with controls. Positive legacy effects of irrigation on ANPP persisted for at least 3 years following treatment reversal, were apparent in both wet and dry years, and were associated with altered plant functional composition. In contrast, legacy effects on soil respiration were comparatively short-lived and did not manifest under natural or experimentally-imposed "wet years," suggesting that legacy effects on CO2 efflux are contingent on current conditions. Although total soil C remained similar across treatments, long-term irrigation increased labile soil C and the sensitivity of microbial biomass C to drought. Importantly, the magnitude of legacy effects for all response variables varied with topography, suggesting that landscape can modulate the strength and direction of climate legacies. Our results demonstrate the role of climate history as an important determinant of terrestrial C cycling responses to future climate changes.

Cross-Site Comparisons of Dryland Ecosystem Response to Climate Change in the US Long-Term Ecological Research Network.

Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.

Safe and rapid radial hemostasis achieved using a novel topical hemostatic patch: Results of a first-in-human pilot study using hydrophobically modified polysaccharide-chitosan.

BACKGROUND: The transradial approach (TRA) for catheter interventions decreases vascular complications and bleeding versus transfemoral approach. Reducing time to hemostasis and preventing radial artery occlusion (RAO) following TRA are important and incompletely realized aspirations. OBJECTIVES: This first-in-human study sought to evaluate the efficacy of a novel, topically applied compound (hydrophobically modified polysaccharide-chitosan, hm-P) plus minimal required pneumatic compression, to achieve rapid radial arterial hemostasis in post-TRA procedures compared with de facto standards. MATERIALS AND METHODS: About 50 adult patients undergoing 6 French diagnostic TRA procedures were prospectively enrolled. At procedure completion, a topical hm-P impregnated patch was placed over the dermotomy and TR Band (TRB) compression was applied to the access site. This patch was used as part of a novel rapid deflation protocol with a primary outcome of time to hemostasis. Photographic and vascular ultrasound evaluation of the radial artery was performed to evaluate the procedural site. RESULTS: Time to hemostasis was 40.5 min (IQR: 38-50 min) with the majority of patients (n = 39, 78%) not requiring reinflation. Patients with bleeding requiring TRB reinflation were more likely to have low body weight and liver dysfunction, with absence of hypertension and LV dysfunction. The rate of RAO was 0% with predischarge radial artery patency documented in all patients using vascular ultrasound. One superficial hematoma was noted. No late bleeding events or cutaneous reactions were reported in the study follow-up. CONCLUSIONS: Topical application of hm-P in conjunction with pneumatic compression was safe and resulted in rapid and predictable hemostasis at the arterial puncture site.

Global change effects on plant communities are magnified by time and the number of global change factors imposed.

Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity-ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.

Fire frequency, state change and hysteresis in tallgrass prairie.

Hysteresis is a fundamental characteristic of alternative stable state theory, yet evidence of hysteresis is rare. In mesic grasslands, fire frequency regulates transition from grass- to shrub-dominated system states. It is uncertain, however, if increasing fire frequency can reverse shrub expansion, or if grass-shrub dynamics exhibit hysteresis. We implemented annual burning in two infrequently burned grasslands and ceased burning in two grasslands burned annually. With annual fires, grassland composition converged on that of long-term annually burned vegetation due to rapid recovery of grass cover, although shrubs persisted. When annual burning ceased, shrub cover increased, but community composition did not converge with a long-term infrequently burned reference site because of stochastic and lagged dispersal by shrubs, reflecting hysteresis. Our results demonstrated that annual burning can slow, but not reverse, shrub encroachment. In addition, reversing fire frequencies resulted in hysteresis because vegetation trajectories from grassland to shrubland differed from those of shrubland to grassland.

Aortic Pulsatility Index: A Novel Hemodynamic Variable for Evaluation of Decompensated Heart Failure.

BACKGROUND: Right heart catheterization for invasive hemodynamics has shown only modest correlation with clinical outcomes. We designed a novel hemodynamic variable that incorporates ventricular output and filling pressure. We anticipated that the aortic pulsatility index (API) would correlate with clinical outcomes in patients with heart failure. METHODS AND RESULTS: We retrospectively analyzed consecutive patients undergoing right heart catheterization with milrinone drug study at our institution (February 2013 to November 2019). The API was calculated as (systolic blood pressure - diastolic blood pressure)/pulmonary capillary wedge pressure. The primary outcome was freedom from advanced therapies, defined as the need for inotropes, temporary mechanical circulatory support, a left ventricular assist device, or orthotopic heart transplantation, or death at 30 days. A total of 224 patient encounters, age 57 years (48-66 years; 34% women; 31% ischemic cardiomyopathy) were included. In univariable analysis, lower baseline API was significantly associated with progression to advanced therapies or death at 30-days (odds ratio 0.43, 95% confidence interval 0.30-0.61; P < .001) compared with those on continued medical management. Receiver operator characteristic analysis specified an optimal cutpoint of 1.45 for API. A Kaplan-Meier analysis indicated an association of API with the primary outcome (79% for API ≥ 1.45 vs 48% for API < 1.45). In multivariable analysis, higher API was strongly associated with freedom from advanced therapies or death (odds ratio 0.38, 95% confidence interval 0.22-0.65, P ≤ .001), even when adjusted for baseline characteristics and routine right heart catheterization measurements. CONCLUSIONS: The API is a novel invasive hemodynamic measurement that is associated independently with freedom from advanced therapies or death at 30-day follow-up.

Safety and efficacy of catheter-directed therapy versus anticoagulation alone in a higher-risk acute pulmonary embolism population.

There is little data comparing safety and efficacy outcomes in patients with pulmonary embolism (PE) receiving catheter directed therapies (CDT) compared to a similar-risk cohort of PE patients receiving anticoagulation alone. 1094 patients with acute PE were studied. CDT and conservatively-managed patients were compared using propensity score matching to assess safety outcomes, which included bleeding and acute kidney injury at 2 and 7 days after PE diagnosis. Efficacy outcomes included change in vital signs over 72 h and in-hospital mortality. PE patients with RV strain who underwent CDT (n = 76) had more bleeding at 2 days (additional 1.04 g/dL loss, 95% CI - 1.48 to - 0.60, p < 0.001) and 7 days (additional 1.36 g/dL loss, 95% CI - 1.88 to - 0.84, p < 0.001) compared to those receiving anticoagulation alone (n = 303). There was a significant increase in creatinine at 2 days (additional 0.22 mg/dL elevation, 95% CI 0.02 to 0.42, p = 0.03), but not at 7 days (additional 0.12 mg/dL elevation, 95% CI - 0.11 to 0.35, p = 0.30). In-hospital mortality for patients receiving CDT versus anticoagulation alone was similar (OR 1.21, 95% CI 0.53 to 2.77; p = 0.65). In patients with baseline abnormal vital signs who received CDT versus anticoagulation alone, heart rate, respiratory rate and oxygen requirement improved significantly faster and to levels closer to normal (p ≤ 0.001). CDT was associated with a small but increased risk of bleeding, but no significant worsening of renal function. CDT may be associated with more rapid improvements in heart rate, respiratory rate, and oxygen requirement.

Two-year follow-up of bioresorbable vascular scaffolds in severe infra-popliteal arterial disease.

OBJECTIVES: To assess the safety, efficacy, and durability of the Absorb bioresorbable vascular scaffold in predominantly complex, infra-popliteal lesions for the management of chronic limb ischemia at two-year clinical follow-up. Bioresorbable vascular scaffold are biodegradable scaffolds that provide short-term vascular support before undergoing intravascular degradation. A recent trial reported excellent 36-month vessel patency rates in simple infrapopliteal arterial lesions treated with Absorb bioresorbable vascular scaffold. METHODS: This single-center, retrospective study evaluated the use of the Absorb bioresorbable vascular scaffold (everolimus impregnated poly-L-lactic scaffold) in patients with infra-popliteal peripheral arterial disease (PAD) with respect to safety (thrombosis and TIMI bleeding), technical success, and freedom from clinically driven target vessel failure at 24 months. RESULTS: 31 patients (51.6% male) with a median age of 67 years with predominantly advanced infra-popliteal disease were treated with 49 bioresorbable vascular scaffold in 41 vessels. The mean stenosis was 94% (80-100), with 49% of lesions being chronic thrombotic occlusions. No scaffold thrombosis or peri-procedural bleeding was observed. Procedural success was achieved in all patients; 93.5% of patients experienced freedom from clinically driven target vessel failure at 24 months, driven by one revascularization and one amputation. Primary patency was 96.7% at 12 months and 87.1% at 24 months. All patients were alive at 12 and 24 months. CONCLUSIONS: At 24 months, our study found that patients with predominantly advanced infra-popliteal PAD who were treated with Absorb bioresorbable vascular scaffold reported improved clinical status and a low and durable rate of clinically driven target vessel failure extending out to 24 months.

New frontiers in modeling tuberous sclerosis with human stem cell-derived neurons and brain organoids.

Recent advances in human stem cell and genome engineering have enabled the generation of genetically defined human cellular models for brain disorders. These models can be established from a patient's own cells and can be genetically engineered to generate isogenic, controlled systems for mechanistic studies. Given the challenges of obtaining and working with primary human brain tissue, these models fill a critical gap in our understanding of normal and abnormal human brain development and provide an important complement to animal models. Recently, there has been major progress in modeling the neuropathophysiology of the canonical "mTORopathy" tuberous sclerosis complex (TSC) with such approaches. Studies using two- and three-dimensional cultures of human neurons and glia have provided new insights into how mutations in the TSC1 and TSC2 genes impact human neural development and function. Here we discuss recent progress in human stem cell-based modeling of TSC and highlight challenges and opportunities for further efforts in this area.

Cardiorenal Syndrome: Classification, Pathophysiology, Diagnosis, and Treatment Strategies: A Scientific Statement From the American Heart Association.

Cardiorenal syndrome encompasses a spectrum of disorders involving both the heart and kidneys in which acute or chronic dysfunction in 1 organ may induce acute or chronic dysfunction in the other organ. It represents the confluence of heart-kidney interactions across several interfaces. These include the hemodynamic cross-talk between the failing heart and the response of the kidneys and vice versa, as well as alterations in neurohormonal markers and inflammatory molecular signatures characteristic of its clinical phenotypes. The mission of this scientific statement is to describe the epidemiology and pathogenesis of cardiorenal syndrome in the context of the continuously evolving nature of its clinicopathological description over the past decade. It also describes diagnostic and therapeutic strategies applicable to cardiorenal syndrome, summarizes cardiac-kidney interactions in special populations such as patients with diabetes mellitus and kidney transplant recipients, and emphasizes the role of palliative care in patients with cardiorenal syndrome. Finally, it outlines the need for a cardiorenal education track that will guide future cardiorenal trials and integrate the clinical and research needs of this important field in the future.

Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties.

Soil nitrogen (N) availability is critical for grassland functioning. However, human activities have increased the supply of biologically limiting nutrients, and changed the density and identity of mammalian herbivores. These anthropogenic changes may alter net soil N mineralization (soil net Nmin ), that is, the net balance between N mineralization and immobilization, which could severely impact grassland structure and functioning. Yet, to date, little is known about how fertilization and herbivore removal individually, or jointly, affect soil net Nmin across a wide range of grasslands that vary in soil and climatic properties. Here we collected data from 22 grasslands on five continents, all part of a globally replicated experiment, to assess how fertilization and herbivore removal affected potential (laboratory-based) and realized (field-based) soil net Nmin . Herbivore removal in the absence of fertilization did not alter potential and realized soil net Nmin . However, fertilization alone and in combination with herbivore removal consistently increased potential soil net Nmin. Realized soil net Nmin , in contrast, significantly decreased in fertilized plots where herbivores were removed. Treatment effects on potential and realized soil net Nmin were contingent on site-specific soil and climatic properties. Fertilization effects on potential soil net Nmin were larger at sites with higher mean annual precipitation (MAP) and temperature of the wettest quarter (T.q.wet). Reciprocally, realized soil net Nmin declined most strongly with fertilization and herbivore removal at sites with lower MAP and higher T.q.wet. In summary, our findings show that anthropogenic nutrient enrichment, herbivore exclusion and alterations in future climatic conditions can negatively impact soil net Nmin across global grasslands under realistic field conditions. This is an important context-dependent knowledge for grassland management worldwide.

Soil heterogeneity increases plant diversity after 20 years of manipulation during grassland restoration.

The "environmental heterogeneity hypothesis" predicts that variability in resources promotes species coexistence, but few experiments support this hypothesis in plant communities. A previous 15-yr test of this hypothesis in a prairie restoration experiment demonstrated a weak effect of manipulated soil resource heterogeneity on plant diversity. This response was attributed to a transient increase in richness following a post-restoration supplemental propagule addition, occasionally higher diversity under nutrient enrichment, and reduced cover of a dominant species in a subset of soil treatments. Here, we report community dynamics under continuous propagule addition in the same experiment, corresponding to 16-20 yr of restoration, in response to altered availability and heterogeneity of soil resources. We also quantified traits of newly added species to determine if heterogeneity increases the amount and variety of niches available for new species to exploit. The heterogeneous treatment contained a factorial combination of altered nutrient availability and soil depth; control plots had no manipulations. Total diversity and richness were higher in the heterogeneous treatment during this 5-yr study due to higher cover, diversity, and richness of previously established forbs, particularly in the N-enriched subplots. All new species added to the experiment exhibited unique trait spaces, but there was no evidence that heterogeneous plots contained a greater variety of new species representing a wider range of trait spaces relative to the control treatment. The richness and cover of new species was higher in N-enriched soil, but the magnitude of this response was small. Communities assembling under long-term N addition were dominated by different species among subplots receiving added N, leading to greater dispersion of communities among the heterogeneous relative to control plots. Contrary to the deterministic mechanism by which heterogeneity was expected to increase diversity (greater variability in resources for new species to exploit), higher diversity in the heterogeneous plots resulted from destabilization of formerly grass-dominated communities in N-enriched subplots. While we do not advocate increasing available soil N at large scales, we conclude that the positive effect of environmental heterogeneity on diversity can take decades to materialize and depend on development of stochastic processes in communities with strong establishment limitation.

Performance of the right ventricular outflow tract/aortic diameter as a novel predictor of risk in patients with acute pulmonary embolism.

Right ventricular (RV) enlargement, determined via the ratio of the right to left ventricular diameters (RV/LV) by CT imaging is used to classify the severity of acute pulmonary embolism (PE) and impacts treatment decisions. The RV/LV ratio may be an unreliable marker of RV dysfunction, due in part to the complex RV geometry. This study compared the RV/LV ratio to a novel metric, the ratio of the right ventricular to aortic outflow tract diameters (RVOT/Ao) in patients with acute PE treated with catheter-directed therapies (CDT). RVOT/Ao and RV/LV ratios were measured on CT images from 103 patients who received CDT for acute submassive or massive PE and were compared to RV dysfunction severity determined by transthoracic echocardiography. Ratios and biomarkers on admission were assessed for correlation with invasively-measured hemodynamics [right atrial (RA) pressure, mean pulmonary artery (PA) pressure, cardiac output (CO)]. RVOT/Ao but not RV/LV ratios were increased in patients with moderate or severe RV dysfunction compared to those without RV dysfunction (p < 0.05). Neither ratio showed significant correlation with RA (r = 0.09 vs 0.055, p > 0.05), mean PA pressure (r = 0.167 vs 0.146, p > 0.05), or CO (r = 0.021 vs - 0.183, p > 0.05). proBNP correlated with mean PA pressure (r = 0.377, p < 0.05). The RVOT/Ao ratio may be better at assessing RV dysfunction than the RV/LV ratio in patients presenting with acute PE. Although currently accepted protocols rely on the RV/LV ratio in determining when CDT are of benefit, the RVOT/Ao ratio may be a more useful tool in identifying high risk patients.

Monocyte and macrophage subtypes as paired cell biomarkers for coronary artery disease.

NEW FINDINGS: What is the central question of this study? Are circulating monocyte markers correlated with their derived macrophage polarization patterns and coronary artery disease severity? What is the main finding and its importance? There was an inverse relationship between circulating CD16+ monocytes (high) and M2 macrophages (low) that marked coronary disease severity, and the differences in polarization of macrophages were seen despite a week of cell culture ex vivo. This study highlights the importance, and potential prognostic implications, of circulating monocyte and descendant macrophage phenotypes in coronary artery disease. ABSTRACT: Monocytes and macrophages are central to atherosclerosis, but how they combine to mark progression of human coronary artery disease (CAD) is unclear. We tested whether patients' monocyte subtypes paired with their derived macrophage profiles were correlated with extent of CAD. Peripheral blood was collected from 40 patients undergoing cardiac catheterization, and patients were categorized as having no significant CAD, single vessel disease or multivessel disease according to the number of affected coronary arteries. Mononuclear cells were measured for the monocyte markers CD14 and CD16 by flow cytometry, and separate monocytes were cultured into macrophages over 7 days and measured for the polarization markers CD86 and CD206. At baseline, patients with a greater CAD burden were older, with higher rates of statin, ß-blocker and antiplatelet drug use, whereas other characteristics were similar across the spectrum of coronary disease. CD16+ (both intermediate and non-classical) monocytes were elevated in patients with single vessel and multivessel disease compared with those without significant CAD (P < 0.05), whereas regulatory M2 macrophages (CD206+ ) were decreased in patients with single vessel and multivessel disease (P < 0.001). An inverse relationship between paired CD16+ monocytes and M2 macrophages marked CAD severity. On multivariable linear regression, CAD severity was associated, along with age and traditional cardiovascular risk factors, with CD16+ monocytes (directly) and M2 macrophages (inversely). Circulating monocytes may influence downstream polarization of lesional macrophages, and these measures of monocyte and macrophage subtypes hold potential as biomarkers in CAD.