Climate change-induced stress disrupts ectomycorrhizal interaction networks at the boreal-temperate ecotone.

The interaction networks formed by ectomycorrhizal fungi (EMF) and their tree hosts, which are important to both forest recruitment and ecosystem carbon and nutrient retention, may be particularly susceptible to climate change at the boreal-temperate forest ecotone where environmental conditions are changing rapidly. Here, we quantified the compositional and functional trait responses of EMF communities and their interaction networks with two boreal (Pinus banksiana and Betula papyrifera) and two temperate (Pinus strobus and Quercus macrocarpa) hosts to a factorial combination of experimentally elevated temperatures and reduced rainfall in a long-term open-air field experiment. The study was conducted at the B4WarmED (Boreal Forest Warming at an Ecotone in Danger) experiment in Minnesota, USA, where infrared lamps and buried heating cables elevate temperatures (ambient, +3.1 °C) and rain-out shelters reduce growing season precipitation (ambient, ~30% reduction). EMF communities were characterized and interaction networks inferred from metabarcoding of fungal-colonized root tips. Warming and rainfall reduction significantly altered EMF community composition, leading to an increase in the relative abundance of EMF with contact-short distance exploration types. These compositional changes, which likely limited the capacity for mycelial connections between trees, corresponded with shifts from highly redundant EMF interaction networks under ambient conditions to less redundant (more specialized) networks. Further, the observed changes in EMF communities and interaction networks were correlated with changes in soil moisture and host photosynthesis. Collectively, these results indicate that the projected changes in climate will likely lead to significant shifts in the traits, structure, and integrity of EMF communities as well as their interaction networks in forest ecosystems at the boreal-temperate ecotone.

Interventional cardiologist perceptions about PCI without surgical backup-Results of an international survey.

BACKGROUND: Percutaneous coronary intervention (PCI) without surgical backup is becoming increasingly common in the United States. Additionally, a recent SCAI expert consensus document has liberalized recommendations for performing PCI without cardiac surgery on site (SOS). AIMS: The current study sought to understand practice patterns and operator preferences with regard to performing PCI without SOS. METHODS: Two internet-based surveys were distributed to interventional cardiologists worldwide. Survey items asked about operator demographics, procedural preferences when performing PCI without SOS, self-judged personality traits, and history of malpractice. RESULTS: Between March 2021 and May 2021, 517 interventional cardiologists completed the survey; 341 of whom perform elective PCI without SOS (no-SOS operators), and 176 who perform elective PCI with surgical backup (SOS operators). Most operators were male 473 (91.5%). There was a greater proportion of SOS operators in academic practice (86 vs. 75, p < 0.001) and greater proportion of no-SOS operators in hospital-owned practices (158 vs. 56, p < 0.001). Lesion characteristics (left main, chronic total occlusions, and need for atherectomy) were the most important procedural attributes for no-SOS operators, and international operators reported higher comfort levels with PCI on high-risk lesions. Cumulative personality profile scores were similar between SOS and no-SOS operators. SOS operators expressed more concern with legal ramifications of performing PCI without SOS (2.57 vs. 2.34, p = 0.049). CONCLUSIONS: In the absence of surgical backup, lesion characteristics were the most important consideration for PCI patient selection for operators worldwide. Compared to the United States, international operators were more confident in performing high-risk PCI without surgical backup.

Warming drives a 'hummockification' of microbial communities associated with decomposing mycorrhizal fungal necromass in peatlands.

Dead fungal mycelium (necromass) represents a critical component of soil carbon (C) and nutrient cycles. Assessing how the microbial communities associated with decomposing fungal necromass change as global temperatures rise will help in determining how these belowground organic matter inputs contribute to ecosystem responses. In this study, we characterized the structure of bacterial and fungal communities associated with multiple types of decaying mycorrhizal fungal necromass incubated within mesh bags across a 9°C whole ecosystem temperature enhancement in a boreal peatland. We found major taxonomic and functional shifts in the microbial communities present on decaying mycorrhizal fungal necromass in response to warming. These changes were most pronounced in hollow microsites, which showed convergence towards the necromass-associated microbial communities present in unwarmed hummocks. We also observed a high colonization of ericoid mycorrhizal fungal necromass by fungi from the same genera as the necromass. These results indicate that microbial communities associated with mycorrhizal fungal necromass decomposition are likely to change significantly with future climate warming, which may have strong impacts on soil biogeochemical cycles in peatlands. Additionally, the high enrichment of congeneric fungal decomposers on ericoid mycorrhizal necromass may help to explain the increase in ericoid shrub dominance in warming peatlands.

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.

Decelerated carbon cycling by ectomycorrhizal fungi is controlled by substrate quality and community composition.

Interactions between symbiotic ectomycorrhizal (EM) and free-living saprotrophs can result in significant deceleration of leaf litter decomposition. While this phenomenon is widely cited, its generality remains unclear, as both the direction and magnitude of EM fungal effects on leaf litter decomposition have been shown to vary among studies. Here we explicitly examine how contrasting leaf litter types and EM fungal communities may lead to differential effects on carbon (C) and nitrogen (N) cycling. Specifically, we measured the response of soil nutrient cycling, litter decay rates, litter chemistry and fungal community structure to the reduction of EM fungi (via trenching) with a reciprocal litter transplant experiment in adjacent Pinus- or Quercus-dominated sites. We found clear evidence of EM fungal suppression of C and N cycling in the Pinus-dominated site, but no suppression in the Quercus-dominated site. Additionally, in the Pinus-dominated site, only the Pinus litter decay rates were decelerated by EM fungi and were associated with decoupling of litter C and N cycling. Our results support the hypothesis that EM fungi can decelerate C cycling via N competition, but strongly suggest that the 'Gadgil effect' is dependent on both substrate quality and EM fungal community composition. We argue that understanding tree host traits as well as EM fungal functional diversity is critical to a more mechanistic understanding of how EM fungi mediate forest soil biogeochemical cycling.

Improving fetal congenital heart disease screening using a checklist-based approach.

To determine if using a checklist of specific ultrasound image criteria to screen the fetal heart improves the cardiac exam completion rate, defined as the ability to classify the heart as normal or abnormal. This is a retrospective cohort study of patients with singleton pregnancies who underwent a fetal anatomy survey between 18 and 28 weeks' gestation. A checklist was used from 1 September 2015 to 31 March 2016 to categorize exams as complete-normal, complete-abnormal, or incomplete. Performance was compared with a 7-month period prior to checklist introduction (1 December 2014 to 30 June 2015). Checklist utilization improved the cardiac exam completion rate by 8.9%. With the checklist, 1083 of 1202 exams (90.1%) were completed compared to 987 of 1193 (82.7%) pre-checklist, P < .001. We did not detect a change in cases classified as abnormal and referred for echocardiography: 25 (2.1%) with the checklist and 16 (1.3%) pre-checklist, P = .16. We did not detect more congenital heart disease (CHD), 12 (1.0%) with checklist screening, 5 (0.4%) pre-checklist, P = .14. Critical CHD was not missed in either group. Using the checklist improved the cardiac exam completion rate. There was no change in congenital heart disease detection.

Melanin mitigates the accelerated decay of mycorrhizal necromass with peatland warming.

Despite being a significant input into soil carbon pools of many high-latitude ecosystems, little is known about the effects of climate change on the turnover of mycorrhizal fungal necromass. Here, we present results from the first experiment examining the effects of climate change on the long-term decomposition of mycorrhizal necromass, utilising the Spruce and Peatland Response Under Changing Environments (SPRUCE) experiment. Warming significantly increased necromass decomposition rates but was strongest in normally submerged microsites where warming caused water table drawdown. Necromass chemistry exerted the strongest control on the decomposition, with initial nitrogen content strongly predicting early decay rates (3 months) and initial melanin content determining mass remaining after 2 years. Collectively, our results suggest that as global temperatures rise, variation in species biochemical traits as well as microsites where mycorrhizal necromass is deposited will determine how these important inputs contribute to the belowground storage of carbon in boreal peatlands.

Exploring the role of ectomycorrhizal fungi in soil carbon dynamics.

The extent to which ectomycorrhizal (ECM) fungi enable plants to access organic nitrogen (N) bound in soil organic matter (SOM) and transfer this growth-limiting nutrient to their plant host, has important implications for our understanding of plant-fungal interactions, and the cycling and storage of carbon (C) and N in terrestrial ecosystems. Empirical evidence currently supports a range of perspectives, suggesting that ECM vary in their ability to provide their host with N bound in SOM, and that this capacity can both positively and negatively influence soil C storage. To help resolve the multiplicity of observations, we gathered a group of researchers to explore the role of ECM fungi in soil C dynamics, and propose new directions that hold promise to resolve competing hypotheses and contrasting observations. In this Viewpoint, we summarize these deliberations and identify areas of inquiry that hold promise for increasing our understanding of these fundamental and widespread plant symbionts and their role in ecosystem-level biogeochemistry.

Contemporary transradial access practices: Results of the second international survey.

OBJECTIVES: To gain insight into current practice of transradial angiography and intervention in the United States and around the world. BACKGROUND: Transradial access (TRA) has grown worldwide. In a prior survey, there was significant practice variation and there was minimal US participation which limited the generalizability to US operators. METHODS: We used an internet-based survey software program to solicit input from practicing interventional cardiologists from the United States and around the world. US operators were compared with outside the United States (OUS) operators and respondent-level comparisons were made with the prior survey to assess for temporal changes in practice. RESULTS: Between August 2016 and January 1, 2017, 125 interventional cardiologists completed the survey representing 91 countries with the United States having 449 (39.9%) respondents. Preprocedure, noninvasive testing for collateral circulation is used more commonly in the United States (54.1%) than around the world (26.6%) but its use has decreased since 2010. In the US, 48.8% of operators never use ultrasound and 92.6% of OUS operators never use it; only 4.4% overall use ultrasound in >50% of cases. Use of bivalirudin has decreased in the US and OUS. Nearly, 30% of operators do not assess for radial artery patency following hemostasis. US respondents used TRA less commonly for primary PCI for STEMI than their global counterparts. CONCLUSIONS: There is wide variation in how TRA procedures are performed including relatively low rates of adherence to practices that are known to improve outcomes. Further education aimed at increasing use of best practices will impact patient outcomes.

The continuing relevance of "older" mycorrhiza literature: insights from the work of John Laker Harley (1911-1990).

To new generations of scientists beginning their careers in research, we strongly recommend the practice of reading older literature. To illustrate the value of doing so, we highlight six insights of one of the most influential mycorrhiza researchers of the twentieth century, Jack Harley. These insights concerning mycotrophy, the new niche, the sheath, C cycling, N cycling, and mutualism were published prior to 1975 and so may have escaped the notice of many, but they laid the groundwork for some of the most important research of today.

Building a better foundation: improving root-trait measurements to understand and model plant and ecosystem processes.

Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine roots and other plant organs is limited. Here we discuss three underappreciated areas where focused measurements of fine-root traits can make significant contributions to ecosystem science. These include assessment of spatiotemporal variation in fine-root traits, integration of mycorrhizal fungi into fine-root-trait frameworks, and the need for improved scaling of traits measured on individual roots to ecosystem-level processes. Progress in each of these areas is providing opportunities to revisit how below-ground processes are represented in terrestrial biosphere models. Targeted measurements of fine-root traits with clear linkages to ecosystem processes and plant responses to environmental change are strongly needed to reduce empirical and model uncertainties. Further identifying how and when suites of root and whole-plant traits are coordinated or decoupled will ultimately provide a powerful tool for modeling plant form and function at local and global scales.

Ectomycorrhizal fungal response to warming is linked to poor host performance at the boreal-temperate ecotone.

Rising temperatures associated with climate change have been shown to negatively affect the photosynthetic rates of boreal forest tree saplings at their southern range limits. To quantify the responses of ectomycorrhizal (EM) fungal communities associated with poorly performing hosts, we sampled the roots of Betula papyrifera and Abies balsamea saplings growing in the B4Warmed (Boreal Forest Warming at an Ecotone in Danger) experiment. EM fungi on the root systems of both hosts were compared from ambient and +3.4 °C air and soil warmed plots at two sites in northern Minnesota. EM fungal communities were assessed with high-throughput sequencing along with measures of plant photosynthesis, soil temperature, moisture, and nitrogen. Warming selectively altered EM fungal community composition at both the phylum and genus levels, but had no significant effect on EM fungal operational taxonomic unit (OTU) diversity. Notably, warming strongly favored EM Ascomycetes and EM fungi with short-contact hyphal exploration types. Declining host photosynthetic rates were also significantly inversely correlated with EM Ascomycete and EM short-contact exploration type abundance, which may reflect a shift to less carbon demanding fungi due to lower photosynthetic capacity. Given the variation in EM host responses to warming, both within and between ecosystems, better understanding the link between host performance and EM fungal community structure will to clarify how climate change effects cascade belowground.

Head injury serum markers for assessing response to trauma: Design of the HeadSMART study.

BACKGROUND: Accurate diagnosis and risk stratification of traumatic brain injury (TBI) at time of presentation remains a clinical challenge. The Head Injury Serum Markers for Assessing Response to Trauma study (HeadSMART) aims to examine blood-based biomarkers for diagnosing and determining prognosis in TBI. METHODS: HeadSMART is a 6-month prospective cohort study comparing emergency department patients evaluated for TBI (exposure group) to (1) emergency department patients evaluated for traumatic injury without head trauma and (2) healthy persons. Study methods and characteristics of the first 300 exposure participants are discussed. RESULTS: Of the first 300 participants in the exposure arm, 70% met the American Congress of Rehabilitation Medicine criteria for TBI, with the majority (80.1%) classified as mild TBI. The majority of subjects in the exposure arm had Glasgow Coma Scale scores of 13-15 (98.0%), normal head computed tomography (81.3%) and no prior history of concussion (71.7%). CONCLUSION: With systematic phenotyping, HeadSMART will facilitate diagnosis and risk-stratification of the heterogeneous group of individuals currently diagnosed with TBI.

Revisiting the 'Gadgil effect': do interguild fungal interactions control carbon cycling in forest soils?

In forest ecosystems, ectomycorrhizal and saprotrophic fungi play a central role in the breakdown of soil organic matter (SOM). Competition between these two fungal guilds has long been hypothesized to lead to suppression of decomposition rates, a phenomenon known as the 'Gadgil effect'. In this review, we examine the documentation, generality, and potential mechanisms involved in the 'Gadgil effect'. We find that the influence of ectomycorrhizal fungi on litter and SOM decomposition is much more variable than previously recognized. To explain the inconsistency in size and direction of the 'Gadgil effect', we argue that a better understanding of underlying mechanisms is required. We discuss the strengths and weaknesses of each of the primary mechanisms proposed to date and how using different experimental methods (trenching, girdling, microcosms), as well as considering different temporal and spatial scales, could influence the conclusions drawn about this phenomenon. Finally, we suggest that combining new research tools such as high-throughput sequencing with experiments utilizing natural environmental gradients will significantly deepen our understanding of the 'Gadgil effect' and its consequences on forest soil carbon and nutrient cycling.

Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes.

Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine-root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine-root orders. Here, we demonstrate how order-based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter-lived absorptive pool and a longer-lived transport fine-root pool. Using these frameworks, we estimate that fine-root production and turnover represent 22% of terrestrial net primary production globally - a c. 30% reduction from previous estimates assuming a single fine-root pool. Future work developing tools to rapidly differentiate functional fine-root classes, explicit incorporation of mycorrhizal fungi into fine-root studies, and wider adoption of a two-pool approach to model fine roots provide opportunities to better understand below-ground processes in the terrestrial biosphere.

Determining place and process: functional traits of ectomycorrhizal fungi that affect both community structure and ecosystem function.

There is a growing interest amongst community ecologists in functional traits. Response traits determine membership in communities. Effect traits influence ecosystem function. One goal of community ecology is to predict the effect of environmental change on ecosystem function. Environmental change can directly and indirectly affect ecosystem function. Indirect effects are mediated through shifts in community structure. It is difficult to predict how environmental change will affect ecosystem function via the indirect route when the change in effect trait distribution is not predictable from the change in response trait distribution. When response traits function as effect traits, however, it becomes possible to predict the indirect effect of environmental change on ecosystem function. Here we illustrate four examples in which key attributes of ectomycorrhizal fungi function as both response and effect traits. While plant ecologists have discussed response and effect traits in the context of community structuring and ecosystem function, this approach has not been applied to ectomycorrhizal fungi. This is unfortunate because of the large effects of ectomycorrhizal fungi on ecosystem function. We hope to stimulate further research in this area in the hope of better predicting the ecosystem- and landscape-level effects of the fungi as influenced by changing environmental conditions.

Use of Intravascular Ultrasound and Coronary Angiography to Measure the Prevalence of Myocardial Bridge in Heart Transplant Patients.

Myocardial bridge (MB) detection rates vary across methods and most studies that have assessed MB include symptomatic patients. Intravascular ultrasound (IVUS) is a sensitive tool for MB detection and donor hearts may serve as a surrogate measure of asymptomatic patients. We used IVUS and coronary angiography to measure MB prevalence in heart transplant patients during routine follow-up invasive coronary assessments. This was a retrospective, single-center study of heart transplant patients who received follow-up coronary assessments at the University of Chicago Heart and Vascular Center between December 2014 and December 2021. A single experienced interventional cardiologist assessed incidental findings of MB in IVUS and coronary angiography. Detection rates were compared with meta-analysis-reported prevalence. Of 129 patients, IVUS-detected MB in 87 patients (67.4%), whereas coronary angiography detected 41 (31.8%). All MB found by coronary angiography were detected by IVUS. Some level of cardiac allograft vasculopathy was found in 92 patients (71.3%). Our IVUS-detected MB prevalence was greater than meta-analysis-reported pooled prevalence across all methods: autopsy, computed tomography angiography, and coronary angiography (67.4% [95% confidence interval [CI] 59.4 to 75.5] vs 42% [95% CI 30 to 55]; 22% [95% CI 18 to 25]; 6% [95% CI 5 to 8], p ≤0.005). The difference between our observed IVUS-detected MB prevalence and meta-analysis autopsy reported MB prevalence was 1.25 (95% CI 1.11 to 1.40). In conclusion, the high prevalence of MB recorded in donor hearts emphasizes the need to further investigate the causes of chest pain in patients who are found to have MB.

The role of chitin in the decomposition of ectomycorrhizal fungal litter.

Ectomycorrhizal fungal tissues comprise a significant forest-litter pool. Ectomycorrhizal (EM) fungi may also influence the decomposition of other forest-litter components via competitive interactions with decomposer fungi and by ensheathing fine roots. Because of these direct and indirect effects of ectomycorrhizal fungi, the factors that control the decomposition of EM fungi will strongly control forest-litter decomposition as a whole and, thus, ecosystem nutrient and carbon cycling. Some have suggested that chitin, a component of fungal cell walls, reduces fungal tissue decomposition because it is relatively recalcitrant. We therefore examined the change in chitin concentrations of EM fungal tissues during decomposition. Our results show that chitin is not recalcitrant relative to other compounds in fungal tissues and that its concentration is positively related to the decomposition of fungal tissues. Variation existing among EM fungal isolates in chitin concentration suggests that EM fungal community structure influences C and nutrient cycling.

Intermittent Blurry Vision: An Unexpected Presentation of Cushing's Syndrome Due to Primary Bilateral Macronodular Adrenal Hyperplasia (PBMAH).

Cushing's syndrome (CS) is an uncommon endocrine disorder resulting from prolonged exposure to elevated glucocorticoids, with 10-15 million annual cases per the American Association of Neurological Surgeons. Exogenous and endogenous causes can further be divided into adrenocorticotropic hormone (ACTH) dependent (i.e Cushing's Disease) or ACTH independent. ACTH-independent CS can be caused by primary bilateral macronodular adrenal hyperplasia (PBMAH) representing less than 1% cases of CS. We report a case of a woman presenting with chronic resistant hypertension, episodic blurry vision, weight gain and wasting of extremities. She was diagnosed with Cushing's syndrome due to PBMAH. Our patient's presentation was unusual as she presented at 40 years old, 10 years earlier than expected for PBMAH; and primarily with complaints of episodic blurry vision. Her symptoms also progressed rapidly as signs and symptoms largely presented over the course of 12 months, however responded well to surgical resection.