A conditional mutation in a wheat (Triticum aestivum L.) gene regulating root morphology.

KEY MESSAGE: Characterisation and genetic mapping of a key gene defining root morphology in bread wheat. Root morphology is central to plants for the efficient uptake up of soil water and mineral nutrients. Here we describe a conditional mutant of hexaploid wheat (Triticum aestivum L.) that when grown in soil with high Ca2+ develops a larger rhizosheath accompanied with shorter roots than the wild type. In wheat, rhizosheath size is a reliable surrogate for root hair length and this was verified in the mutant which possessed longer root hairs than the wild type when grown in high Ca2+ soil. We named the mutant Stumpy and showed it to be due to a single semi-dominant mutation. The short root phenotype at high Ca2+ was due to reduced cellular elongation which might also explain the long root hair phenotype. Analysis of root cell walls showed that the polysaccharide composition of Stumpy roots is remodelled when grown at non-permissive (high) Ca2+ concentrations. The mutation mapped to chromosome 7B and sequencing of the 7B chromosomes in both wild type and Stumpy identified a candidate gene underlying the Stumpy mutation. As part of the process to determine whether the candidate gene was causative, we identified wheat lines in a Cadenza TILLING population with large rhizosheaths but accompanied with normal root length. This finding illustrates the potential of manipulating the gene to disconnect root length from root hair length as a means of developing wheat lines with improved efficiency of nutrient and water uptake. The Stumpy mutant will be valuable for understanding the mechanisms that regulate root morphology in wheat.

Plant-environment microscopy tracks interactions of Bacillus subtilis with plant roots across the entire rhizosphere.

Our understanding of plant-microbe interactions in soil is limited by the difficulty of observing processes at the microscopic scale throughout plants' large volume of influence. Here, we present the development of three-dimensional live microscopy for resolving plant-microbe interactions across the environment of an entire seedling growing in a transparent soil in tailor-made mesocosms, maintaining physical conditions for the culture of both plants and microorganisms. A tailor-made, dual-illumination light sheet system acquired photons scattered from the plant while fluorescence emissions were simultaneously captured from transparent soil particles and labeled microorganisms, allowing the generation of quantitative data on samples ∼3,600 mm3 in size, with as good as 5 µm resolution at a rate of up to one scan every 30 min. The system tracked the movement of Bacillus subtilis populations in the rhizosphere of lettuce plants in real time, revealing previously unseen patterns of activity. Motile bacteria favored small pore spaces over the surface of soil particles, colonizing the root in a pulsatile manner. Migrations appeared to be directed toward the root cap, the point of "first contact," before the subsequent colonization of mature epidermis cells. Our findings show that microscopes dedicated to live environmental studies present an invaluable tool to understand plant-microbe interactions.

Concepts and consequences of the hyphosphere core microbiome for arbuscular mycorrhizal fungal fitness and function.

Arbuscular mycorrhizal (AM) fungi-associated hyphosphere microbiomes can be considered as the second genome of the mycorrhizal phosphorus uptake pathway. Their composition can be thought of as a stably recurring component of a holobiont, defined by the hyphosphere core microbiome, which is thought to benefit AM fungal fitness. Here, we review evidence indicating the existence of the hyphosphere core microbiome, highlight its functions linked to those functions lacking in AM fungi, and further explore the mechanisms by which different core members ensure their stable coexistence. We conclude that deciphering and utilizing the hyphosphere core microbiome provides an entry point for understanding the complex interactions among plants, AM fungi, and bacteria.

A core microbiome in the hyphosphere of arbuscular mycorrhizal fungi has functional significance in organic phosphorus mineralization.

The mycorrhizal pathway is an important phosphorus (P) uptake pathway for more than two-thirds of land plants. The arbuscular mycorrhizal (AM) fungi-associated hyphosphere microbiome has been considered as the second genome of mycorrhizal P uptake pathway and functionality in mobilizing soil organic P (Po). However, whether there is a core microbiome in the hyphosphere and how this is implicated in mining soil Po are less understood. We established on-site field trials located in humid, semiarid, and arid zones and a microcosm experiment in a glasshouse with specific AM fungi and varying soil types to answer the above questions. The hyphosphere microbiome of AM fungi enhanced soil phosphatase activity and promoted Po mineralization in all sites. Although the assemblage of hyphosphere microbiomes identified in three climate zones was mediated by environmental factors, we detected a core set in three sites and the subsequent microcosm experiment. The core members were co-enriched in the hyphosphere and dominated by Alphaproteobacteria, Actinobacteria, and Gammaproteobacteria. Moreover, these core bacterial members aggregate into stable guilds that contributed to phosphatase activity. The core hyphosphere microbiome is taxonomically conserved and provides functions, with respect to the mineralization of Po, that AM fungi lack.

Arbuscular mycorrhizal fungi enhance plant phosphorus uptake through stimulating hyphosphere soil microbiome functional profiles for phosphorus turnover.

The extraradical hyphae of arbuscular mycorrhizal (AM) fungi are colonized by different bacteria in natural and agricultural systems, but the mechanisms by which AM fungi interact with the hyphosphere soil microbiome and influence soil organic phosphorus (P) mobilization remain unclear. We grew Medicago in two-compartment microcosms, inoculated with Rhizophagus irregularis, or not, in the root compartment and set up P treatments (without P, with P addition as KH2 PO4 or nonsoluble phytate) in the hyphal compartment. We studied the processes of soil P turnover and characterized the microbiome functional profiles for P turnover in the hyphosphere soil by metagenomic sequencing. Compared with the bulk soil, the hyphosphere soil of R. irregularis was inhabited by a specific bacterial community and their functional profiles for P turnover was stimulated. At the species level, the shift in hyphosphere soil microbiome was characterized by the recruitment of the genome bin2.39 harbouring both gcd and phoD genes and genome bin2.97 harbouring the phoD gene, which synergistically drove nonsoluble phytate mobilization in the hyphosphere soil. Our results suggest that AM fungi recruits a specific hyphosphere soil microbiome and stimulated their functional profiles for P turnover to enhance utilization of phytate.

The Impact of MOMENTUM 3 Trial Eligibility on Left Ventricular Assist Device Outcomes: A Real-World Experience.

INTRODUCTION: Although the landmark MOMENTUM 3 trial was associated with excellent short-term left ventricular assist device (LVAD) outcomes, many end-stage heart failure patients would not have met the trial eligibility criteria. Moreover, the outcomes of trial ineligible patients are poorly characterized. Therefore, we undertook this study to compare MOMENTUM 3 eligible and ineligible patients. METHODS: We conducted a retrospective review of all primary LVAD implants from 2017 to 2022. Primary stratification was according to MOMENTUM 3 inclusion and exclusion criteria. Primary outcome was survival. Secondary outcomes included complications and length of stay. Multivariable Cox proportional hazards regression models were constructed to further characterize outcomes. RESULTS: From 2017 to 2022, 96 patients underwent primary LVAD implantation. Thirty-seven (38.54%) patients were trial eligible while 59 (61.46%) were ineligible. When stratified by trial eligibility, patients who were trial eligible had higher 1-year (80.15% versus 94.52%, P = 0.04) and 2-year survival (70.17% versus 94.52%, P = 0.02). Multivariable analysis showed that trial eligibility was protective of mortality at both 1 y (HR: 0.19 [0.04-0.99], P = 0.049) and 2 y (HR: 0.17 [0.03-0.81], P = 0.03). Although the groups had similar rates of bleeding, stroke, and right ventricular failure, trial ineligibility was associated with a longer periprocedural length of stay. CONCLUSIONS: In conclusion, the majority of contemporary LVAD patients would not have been eligible for the MOMENTUM 3 trial. Ineligible patients have decreased but acceptable short-term survival. Our findings suggest that a simply reductionist approach to short-term mortality may improve outcomes but fail to capture the majority of patients who could benefit from therapy.

Novel Estimates of Renal Function are Associated with Short-Term Left Ventricular Assist Device Outcomes.

INTRODUCTION: Although preoperative kidney function has been associated with left ventricular assist device (LVAD) outcomes, most previous estimates of glomerular filtration rates (eGFRs) have utilized race in the calculation. Recently, novel eGFR equations independent of race have been suggested and validated. Therefore, we undertook this study to evaluate the predictive value of a novel, non-race-based eGFR calculation on short-term LVAD outcomes. METHODS: We conducted a retrospective review of all primary LVAD implants from 2017 to 2022 at our institution. eGFR was calculated using the novel Chronic Kidney Disease Epidemiology Collaboration 2021 formula (CKD-EPI 2021). eGFR was also calculated according to the Modification of Diet in Renal Disease equation for historical reference. Primary stratification was by eGFR: ≥60, 30-60, and <30. The primary outcome was 1-y survival. Multivariable Cox proportional hazards regression modeling was used to further evaluate the impact of kidney function on 1-y mortality. RESULTS: From 2017 to 2022, 91 patients underwent LVAD implantation with a HeartMate 3 device. The average age was 65.20 ± 11.08, 77 (84.62%) were male, and 14 (15.38%) were Black. The mean CKD-EPI 2021 eGFR was 56.07 ± 23.55 compared with 54.72 ± 26.37 as calculated by Modification of Diet in Renal Disease (P = 0.719). Overall, 30-d and 1-y survival was 96.7% and 85.0%, respectively. When stratified by eGFR, there was a significant difference in 1-y survival (≥60, 93.46%; 30-60, 87.36%; <30, 62.75%; P = 0.016). On multivariable analysis, a preoperative eGFR <30 was associated with an increased hazard of 1-y mortality (5.58 [1.06-29.17], P = 0.043). CONCLUSIONS: In conclusion, non-race-based estimates of renal function are predictive of short-term LVAD outcomes. Further investigation of this phenomenon is warranted.

Temporary Right Ventricular Assist Device Support for Acute Right Heart Failure: A Single-Center Experience.

INTRODUCTION: Severe right ventricular (RV) failure is associated with significant morbidity and mortality. Although right ventricular assist devices (RVADs) are increasingly used for refractory RV failure, there is limited data on their short- and long-term outcomes. Therefore, we undertook this study to better understand our experience with temporary RVADs. METHODS: We conducted a retrospective review of all RVADS performed from 2017 to 2021. Patients supported with surgical RVADs, the Protek Duo device, and the Impella RP device were included. Patients were stratified by the type of RVAD and by etiology of RV failure. Survival was assessed by the Kaplan-Meier method and multivariable Cox proportional hazards regression models. RESULTS: From 2017 to 2021, 42 patients underwent RVAD implantation: 32 with a Protek Duo, 6 with an Impella RP, and 4 with a surgical RVAD. Majority of patients were already supported with an alternate form of mechanical support. Most patients had impaired renal function, decreased hepatic function, and lactic acidosis at the time of cannulation. The median duration of RVAD support was 8.5 [5-19] d. Survival to decannulation was 68.4%, to discharge was 47.4%, and to 1-y was 40.2%. Multivariable analysis identified elevated total bilirubin levels to be associated with 30-d mortality while increased hemoglobin levels were protective. After RVAD cannulation, the median number of pressors and inotropes was lower (P < 0.01) and the lactic acidosis was less (P < 0.01). CONCLUSIONS: In conclusion, RVAD support is associated with lower lactate levels, and decreased number of vasoactive medications, but is associated with significant morbidity and mortality.

Contemporary Outcomes of Isolated Tricuspid Valve Surgery.

INTRODUCTION: Isolated tricuspid valve (TV) surgery is uncommonly performed and has historically been associated with excessive operative mortality. We previously reported improved short-term outcomes at our center. Understanding contemporary outcomes of isolated TV surgery beyond the perioperative period is essential to properly benchmark outcomes of newer transcatheter interventions. METHODS: Patients who underwent isolated TV surgery from 2007 to 2021 at a single institution were retrospectively reviewed. Survival was estimated using the Kaplan-Meier method and multivariable Cox proportional hazards regression modeling identified independent risk factors for all-cause mortality. RESULTS: Among 173 patients undergoing isolated TV surgery, 103 (60%) underwent TV repair and 70 (40%) underwent TV replacement. Mean age was 60.3 ± 18.9 y and 55 (32%) were male. The most common etiology of TV disease was functional (46%). In-hospital mortality was 4.1% (7/173), with no difference between TV repair and replacement (P = 0.06). Overall survival at 1 y and 5 y was 78.3% (111/142) and 64.5% (53/82), respectively. After median (interquartile range) follow-up of 2.0 (0.6-4.4) y, patients undergoing TV repair experienced a higher unadjusted survival as compared to those undergoing TV replacement (log-rank P = 0.02). However, after adjusting for covariates, TV replacement was not an independent predictor of all-cause mortality (hazard ratio 1.40; 95% confidence interval, 0.71-2.76; P = 0.33). CONCLUSIONS: Isolated TV surgery can be performed with lower operative mortality than historically reported. Establishing survival benchmarks from TV surgery is important in the era of developing transcatheter interventions.

Sodium hyperaccumulators in the Caryophyllales are characterized by both abnormally large shoot sodium concentrations and [Na]shoot/[Na]root quotients greater than unity.

BACKGROUND AND AIMS: Some Caryophyllales species accumulate abnormally large shoot sodium (Na) concentrations in non-saline environments. It is not known whether this is a consequence of altered Na partitioning between roots and shoots. This paper tests the hypotheses (1) that Na concentrations in shoots ([Na]shoot) and in roots ([Na]root) are positively correlated among Caryophyllales, and (2) that shoot Na hyperaccumulation is correlated with [Na]shoot/[Na]root quotients. METHODS: Fifty two genotypes, representing 45 Caryophyllales species and 4 species from other angiosperm orders, were grown hydroponically in a non-saline, complete nutrient solution. Concentrations of Na in shoots and in roots were determined using inductively coupled plasma mass spectrometry (ICP-MS). KEY RESULTS: Sodium concentrations in shoots and roots were not correlated among Caryophyllales species with normal [Na]shoot, but were positively correlated among Caryophyllales species with abnormally large [Na]shoot. In addition, Caryophyllales species with abnormally large [Na]shoot had greater [Na]shoot/[Na]root than Caryophyllales species with normal [Na]shoot. CONCLUSIONS: Sodium hyperaccumulators in the Caryophyllales are characterized by abnormally large [Na]shoot, a positive correlation between [Na]shoot and [Na]root, and [Na]shoot/[Na]root quotients greater than unity.

Blood Product Utilization in Patients With COVID-19 on ECMO.

INTRODUCTION: Although extracorporeal membrane oxygenation (ECMO) has been associated with improved outcomes in COVID patients with respiratory failure, data regarding the need for blood product utilization in this population is inadequate. METHODS: We conducted a retrospective review of all COVID patients requiring ECMO support at our facility. Patient demographics, co-morbidities, measures of acuity, and blood product utilization were identified. Patients were stratified by the presence of a major bleed and the need for dialysis. The primary outcome was blood product utilization. Linear regression models were used to assess predictors of the need for blood products. RESULTS: From 2020 to 2021, 41 patients with COVID-19 were included in our study. Overall 1601 d of support, COVID ECMO patients received 755 units of packed red blood cells (PRBC), 51 units of fresh frozen plasma (FFP), 326 platelets, and 1702 cryoprecipitate, amounting to 18.4 units PRBC per patient or 3.30 units per week of ECMO support. Both major bleeding and the need for dialysis were associated with higher rates of transfusion of PRBC, FFP, and platelets. The average non-bleeding COVID ECMO patient who did not need dialysis required 2.17 units of PRBC, 0.12 units of FFP, 0.76 platelets, and 8.36 of cryoprecipitate per week of ECMO support. On multivariable linear regression analysis, each day on ECMO was associated with 0.30 [0.19-0.42, P < 0.01] units of PRBC. CONCLUSIONS: In conclusion, COVID ECMO is associated with a significant need for blood and blood products. Major bleeding and dialysis are important drivers of blood product requirements.

Development of a non-transplant left ventricular assist device program.

INTRODUCTION: Although the established long-term benefit of left ventricular assist device (LVAD) therapy has led to its proliferation as destination therapy (DT), few studies have evaluated LVAD outcomes at nontransplant centers. We undertook this study to better evaluate our experience in building a nontransplant, DT LVAD program. METHODS: We conducted a retrospective review of all LVADs implanted from 2010 to 2021. Patient, operative, and outcome data were extracted from the electronic medical record. Secular trends were evaluated by organizing the data into eras of implant. Survival was assessed using the Kaplan-Meier method. Multivariable Cox proportional hazards regression models further evaluated outcomes. RESULTS: From 2010 to 2021, 100 primary LVAD implants were performed. Annual volume grew from 1 to 30 implants per year. The average age of our cohort was 65.7 years, most patients (80%) were male, 51% had an ischemic etiology, and 65 (65%) were INTERMACS profile 1 or 2. Our 1- and 2-year survival were 82% and 79%, respectively. Multivariable analysis of 1-year mortality demonstrated that decreasing renal function and increased cardiopulmonary bypass (CPB) time were associated with increased mortality while preoperative hemoglobin was protective. When stratified by era of implant, our most recent patients were more likely to be INTERMACS profile 1 or 2; had shorter CPB and aortic cross clamp times; required fewer reoperations for bleeding; and suffered less right ventricular failure requiring mechanical support. CONCLUSIONS: A single, nontransplant LVAD center can experience significant growth in volume in a high-acuity cohort while maintaining acceptable outcomes and quality of care.

Impact of preoperative Impella support on destination left ventricular assist device outcomes.

BACKGROUND: Although left ventricular assist device (LVAD) implantation is associated with improved heart failure survival, the impact of pre-implantation Impella support on outcomes is unknown. We undertook this study to evaluate the impact of preoperative Impella support on LVAD outcomes. METHODS: We conducted a retrospective review of all Heartmate 3 LVAD implants. Primary stratification was by the need for preoperative Impella support with the 5.0/5.5 device. Longitudinal survival was assessed by the Kaplan-Meier method. Multivariable Cox proportional hazards regression models were developed to evaluate mortality. Secondary outcomes included changes in laboratory values during Impella support. RESULTS: From 2017 to 2021, 87 patients underwent LVAD implantation. Sixteen were supported with a single inotrope, 36 with dual inotropes, 27 with Impella, and 3 with extracorporeal membrane oxygenation (ECMO). When stratified by the need for Impella, there was no difference in survival at 30-days (98.3 [88.2-99.8]% vs. 96.3 [76.5-99.5]%, p = .59), 1-year (91.0 [79.8-96.2] vs. 74.9 [51.7-88.2], p = .10), or at 2 years (87.9 [74.3-94.5] vs. 74.9 [51.7-88.2], p = .15). On multivariable modeling, the need for preoperative Impella was not associated with an increased hazard of 1-year (1.24 [0.23-6.73], p = .81) or 2-year mortality (1.05 [0.21-5.19], p = .95). After 7 (5-10) days of Impella support, recipient creatinine (p < .01), creatinine clearance (p = .02), and total bilirubin (p = .053) improved and lactic acidosis resolved (p < .01). CONCLUSIONS: Preoperative Impella support is not associated with increased short or long-term mortality but is associated with improved renal and hepatic function as well as total body perfusion before LVAD implantation.

Extracorporeal membrane oxygenation for respiratory failure in phases of COVID-19 variants.

BACKGROUND: Adaptive mutations of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) virus have emerged throughout the coronavirus disease 2019 (COVID-19) pandemic. The characterization of outcomes in patients requiring extracorporeal membrane oxygenation (ECMO) for severe respiratory distress from COVID-19 during the peak prevalence of different variants is not well known. METHODS: There were 131 patients with laboratory-confirmed SARS-CoV-2 infection supported by ECMO at two referral centers within a large healthcare system. Three predominant variant phase time windows (Pre-Alpha, Alpha, and Delta) were determined by a change-point analyzer based on random population sampling and viral genome sequencing. Patient demographics and outcomes were compared. RESULTS: The average age of patients was 46.9 ± 10.5 years and 70.2% (92/131) were male. Patients cannulated for ECMO during the Delta variant wave were younger compared to earlier Pre-Alpha (39.3 ± 7.8 vs. 48.0 ± 11.1 years) and Alpha phases (39.3 ± 7.8 vs. 47.2 ± 7.7 years) (p < .01). The predominantly affected race in the Pre-Alpha phase was Hispanic (52.2%; 47/90), while in Alpha (61.5%; 16/26) and Delta (40%; 6/15) variant waves, most patients were White (p < .01). Most patients received a tracheostomy (82.4%; 108/131) with a trend toward early intervention in later phases compared to Pre-Alpha (p < .01). There was no significant difference between the duration of ECMO, mechanical support, intensive care unit (ICU) length of stay (LOS), or hospital LOS over the three variant phases. The in-hospital mortality was overall 41.5% (54/131) and was also similar. Six-month survival of patients who survived to discharge was 92.2% (71/77). CONCLUSIONS: There was no significant difference in survival or time on ECMO support in patients during the peak prevalence of the three variants.

Intermediate-term survival and functional outcomes of COVID-19 extracorporeal membrane oxygenation patients.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has been associated with acceptable short-term survival in patients with refractory respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia. Previous studies have demonstrated acceptable long-term outcomes in patients supported with ECMO for respiratory failure of other etiologies. However, long-term survival and functional outcomes in COVID ECMO patients remain unknown. METHODS: We conducted a retrospective review of all COVID patients requiring ECMO at our hospital. The primary outcomes measured were survival to discharge and contemporary survival. Secondary outcomes included two simple functional assessments: the ongoing need for oxygen supplementation and the ability to return to work. Survival was calculated using the Kaplan-Meier method. Hazard ratios were calculated using Cox hazards regression models. RESULTS: From 2020 to 2021, 48 COVID patients have been supported with ECMO at our hospital. Four patients remain on support and were excluded from further analysis. The average age was 47 ± 8 years, 34 (77%) were males, and the plurality (19, 43%) were Hispanic. Median duration of support was 23 (12-51) days. Median follow-up was 106 (29-226) days. Survival to discharge was 59%. Kaplan-Meier 180-day survival was 51%. Long-term survival conditioned on survival to discharge was 89%. In evaluating functional outcomes, the overwhelming majority of patients no longer required oxygen supplementation (74%), and most had returned to work (52%). CONCLUSION: In conclusion, COVID ECMO patients have acceptable intermediate-term survival with adequate functional recovery.

Bloodstream and respiratory coinfections in patients with COVID-19 on ECMO.

BACKGROUND: Although several studies have characterized the risk of coinfection in COVID pneumonia, the risk of the bloodstream and respiratory coinfection in patients with COVID-19 pneumonia on extracorporeal membrane oxygenation (ECMO) supports severe acute respiratory distress syndrome (ARDS) is poorly understood. METHODS: This is a retrospective analysis of patients with COVID-19 ARDS on ECMO at a single center between January 2020 and December 2021. Patient characteristics and clinical outcomes were compared. RESULTS: Of 44 patients placed on ECMO support for COVID-19 ARDS, 30 (68.2%) patients developed a coinfection, and 14 (31.8%) patients did not. Most patients underwent venovenous ECMO (98%; 43/44) cannulation in the right internal jugular vein (98%; 43/44). Patients with coinfection had a longer duration of ECMO (34 [interquartile range, IQR: 19.5, 65] vs. 15.5 [IQR 11, 27.3] days; p = .02), intensive care unit (ICU; 44 [IQR: 27,75.5] vs 31 [IQR 20-39.5] days; p = .03), and hospital (56.5 [IQR 27,75.5] vs 37.5 [IQR: 20.5-43.3]; p = .02) length of stay. When stratified by the presence of a coinfection, there was no difference in hospital mortality (37% vs. 29%; p = .46) or Kaplan-Meier survival (logrank p = .82). Time from ECMO to first positive blood and respiratory culture were 12 [IQR: 3, 28] and 10 [IQR: 1, 15] days, respectively. Freedom from any coinfection was 50 (95% confidence interval: 37.2-67.2)% at 15 days from ECMO initiation. CONCLUSIONS: There is a high rate of co-infections in patients placed on ECMO for COVID-19 ARDS. Although patients with coinfections had a longer duration of extracorporeal life support, and longer length of stays in the ICU and hospital, survival was not inferior.

Early mobilization in coronavirus-19 patients treated with extracorporeal membrane oxygenation.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pneumonia can be associated with refractory respiratory failure requiring extracorporeal membrane oxygenation(ECMO). Although ECMO has helped many COVID patients, optimal management strategies for these patients remain unknown. METHODS: We conducted a retrospective review of all COVID patients requiring ECMO at our hospital. Six months into the pandemic, we changed our management strategy to focus on early mobilization. The early mobilization effort included tracheostomy within 48 h of cannulation, decreasing sedation, and an aggressive physical and occupational therapy program progressing toward early ambulation while on ECMO. The primary outcome measured was survival to discharge. The primary stratification was based on the mobilization strategy. RESULTS: From 2020 to 2021, 47 COVID patients have been supported with ECMO at our institution. Five are still in the hospital on ECMO. 39 (83%) were supported with venovenous ECMO while 8 (17%) were supported with venoarterial or a right ventricular assist device type configuration. All 47 (100%) were cannulated at bedside with transesophageal echocardiographic guidance. The average age was 47 ± 9 years; 36(77%) were male; and 20 (43%) were Hispanic. The median duration of support was 22 (11-44) days. Excluding those who remain in the hospital and on support, overall survival to discharge was 24/42 (57%). When stratified by mobilization strategy, early tracheostomy and mobilization were associated with significantly improved survival (74% [17/23] vs. 37% [7/19], p = .02). There were no changes in patient acuity or duration of support throughout the study period. CONCLUSION: In conclusion, early tracheostomy, decreased sedation, and aggressive mobilization of COVID-19 ECMO patients is associated with improved survival.

Arbuscular mycorrhizal fungi enhance mineralisation of organic phosphorus by carrying bacteria along their extraradical hyphae.

Arbuscular mycorrhizal (AM) fungi gain access to nutrient patches outside the rhizosphere by producing an extensive network of fine hyphae. Here, we focused on establishing the mechanism by which AM fungal hyphae reach discrete organic patches with a cohort of functional bacteria transported in a biofilm on their surface. We investigated the mechanisms and impact of the translocation of phosphate solubilising bacteria (PSB) along AM fungal hyphae in bespoke microcosms. An in vitro culture experiment was also conducted to determine the direct impact of hyphal exudates of AM fungi upon the growth of PSB. The extraradical hyphae of AM fungi can transport PSB to organic phosphorus (P) patches and enhance organic P mineralisation both under in vitro culture and soil conditions. Bacteria move in a thick water film formed around fungal hyphae. However, the bacteria cannot be transferred to the organic P patch without an energy source in the form of hyphal exudates. Our results could be harnessed to better manage plant-microbe interactions and improve the ability of biological inocula involving AM fungi and bacteria to enhance the sustainability of agricultural crops in P limited conditions.

Minimally invasive mitral valve surgery after previous sternotomy: A propensity-matched analysis.

BACKGROUND: Although the incidence of mitral valve (MV) surgery after previous open-heart surgery is increasing, there is no consensus regarding the optimal surgical approach. Reoperative MV surgery is most commonly performed via sternotomy (ST). We sought to determine whether minimally-invasive (MIS) reoperative MV surgery is safe and feasible. METHODS: All patients with a history of ST undergoing MV surgery with or without concomitant tricuspid or atrial fibrillation surgery at a single institution from 2007 to 2018 were retrospectively reviewed. ST and MIS approaches were compared using propensity-matched analysis. The coprimary endpoints were operative mortality and 1-year survival, and secondary endpoints were operative complications and length of stay. RESULTS: A total of 305 isolated MV reoperations were performed: 199 (65%) MIS and 106 (35%) ST. MIS patients were older than ST patients (71 [63, 76.5] vs. 66 [56, 72] years, p < .01), more likely to have undergone prior coronary artery bypass grafting (57% vs. 27%, p < .01), and less likely to have had prior valve surgery (55% vs. 78%, p < .01). In unmatched comparisons, operative mortality was significantly lower among MIS patients (3.0% vs. 8.5%, p = .04), but 1-year mortality was similar (14.4% vs. 15.6%, p = .8). After propensity matching, 88 pairs had excellent balance across baseline characteristics. Mortality was similar among MIS and ST patients at 30 days (3.4% vs. 8%, p = .19) and 1 year (15.9% vs. 16.5%, p = .9). RBC and fresh frozen plasma transfusions were significantly lower in the MIS group (p < .01). CONCLUSIONS: A minimally invasive approach is a safe alternative in patients with prior ST undergoing MV surgery.

Assessing the variation in manganese use efficiency traits in Scottish barley landrace Bere (Hordeum vulgare L.).

BACKGROUND AND AIMS: Manganese (Mn) deficiency in barley is a global problem. It is difficult to detect in the early stages of symptom development and is commonly pre-emptively corrected by Mn foliar sprays that can be costly. Landraces adapted to marginal lands around the world represent a genetic resource for potential sustainability traits including mineral use efficiency. This research aims to confirm novel Mn use efficiency traits from the Scottish landrace Bere and use an association mapping approach to identify genetic loci associated with the trait. METHODS: A hydroponic system was developed to identify and characterize the Mn deficiency tolerance traits in a collection of landraces, including a large number of Scottish Bere barleys, a group of six-rowed heritage landraces grown in the highlands and islands of Scotland. Measuring chlorophyll fluorescence, the effect of Mn deficiency was identified in the early stages of development. Genotypic data, generated using the 50k Illumina iSelect genotyping array, were coupled with the Mn phenotypic data to create a genome-wide association study (GWAS) identifying candidate loci associated with Mn use efficiency. KEY RESULTS: The Bere lines generally had good Mn use efficiency traits. Individual Bere lines showed large efficiencies, with some Bere lines recording almost double chlorophyll fluorescence readings in limited Mn conditions compared with the elite cultivar Scholar. The Mn-efficient Bere lines had increased accumulation of Mn in their shoot biomass compared with elite cultivars, which was highly correlated to the chlorophyll fluorescence. Several candidate genes were identified as being associated with Mn use efficiency in the GWAS. CONCLUSIONS: Several genomic regions for Mn use efficiency traits originating from the Bere lines were identified. Further examination and validation of these regions should be undertaken to identify candidate genes for future breeding for marginal lands.