Comparative proteomics analysis of root and nodule mitochondria of soybean.

Legumes perform symbiotic nitrogen fixation through rhizobial bacteroids housed in specialised root nodules. The biochemical process is energy-intensive and consumes a huge carbon source to generate sufficient reducing power. To maintain the symbiosis, malate is supplied by legume nodules to bacteroids as their major carbon and energy source in return for ammonium ions and nitrogenous compounds. To sustain the carbon supply to bacteroids, nodule cells undergo drastic reorganisation of carbon metabolism. Here, a comprehensive quantitative comparison of the mitochondrial proteomes between root nodules and uninoculated roots was performed using data-independent acquisition proteomics, revealing the modulations in nodule mitochondrial proteins and pathways in response to carbon reallocation. Corroborated our findings with that from the literature, we believe nodules preferably allocate cytosolic phosphoenolpyruvates towards malate synthesis in lieu of pyruvate synthesis, and nodule mitochondria prefer malate over pyruvate as the primary source of NADH for ATP production. Moreover, the differential regulation of respiratory chain-associated proteins suggests that nodule mitochondria could enhance the efficiencies of complexes I and IV for ATP synthesis. This study highlighted a quantitative proteomic view of the mitochondrial adaptation in soybean nodules.

A retrospective cohort study on the clinical outcomes of patients admitted to intensive care units with dysnatremia.

With evolving patient characteristics and patterns of ICU utilization, the impact of dysnatremias on patient outcomes and healthcare costs in the present era have not been well studied. Patients ≥ 18 years admitted to the ICUs in public hospitals in Hong Kong between January 2010 and June 2022 and had at least one serum sodium measurement obtained within 24 h prior to or following ICU admission were stratified into normonatremic (135-145 mmol/L), hyponatremic (< 135 mmol/L) and hypernatremic (> 145 mmol/L) groups. A total of 162,026 patients were included-9098 (5.6%), 40,533 (25.0%) and 112,395 (69.4%) patients were hypernatremic, hyponatremic and normonatremic at the time of ICU admission, respectively. The odds of patients with hypernatremia and hyponatremia dying in the ICU were 27% and 14% higher (aOR 1.27, 95% CI 1.19-1.36 and aOR 1.14, 95% CI 1.08-1.19, respectively; P < 0.001 for both), and 52% and 21% higher for dying in the hospital (aOR 1.52, 95% CI 1.43-1.62 and aOR 1.21, 95% CI 1.17-1.26, respectively; P < 0.001 for both] compared with those with normonatremia. Patients with dysnatremia also had longer ICU length of stay (LOS), hospital LOS, and higher healthcare costs than the normonatremic group. Dysnatremias at ICU admission were associated with increased ICU and in-hospital mortality and overall healthcare burden.

Effects of varying blood flow rate during peripheral veno-arterial extracorporeal membrane oxygen (V-A ECMO) on left ventricular function measured by two-dimensional strain.

Background: We evaluated the effects of varying blood flow rate during peripheral veno-arterial extracorporeal membrane oxygen (V-A ECMO) on left ventricular function measured by two-dimensional strain. Methods: Adult patients who were supported by peripheral V-A ECMO were recruited. Serial hemodynamic and cardiac performance parameters were measured by transthoracic echocardiogram within the first 48 h after implementation of V-A ECMO. Measurements at 100%, 120%, and 50% of target blood flow (TBF) were compared. Results: A total of 54 patients were included and the main indications for V-A ECMO were myocardial infarction [32 (59.3%)] and myocarditis [6 (11.1%)]. With extracorporeal blood flow at 50% compared with 100% TBF, the mean arterial pressure was lower [66 ± 19 vs. 75 ± 18 mmHg, p < 0.001], stroke volume was greater [23 (12-34) vs. 15 (8-26) ml, p < 0.001], and cardiac index was higher [1.2 (0.7-1.7) vs. 0.8 (0.5-1.3) L/min/m2, p < 0.001]. Left ventricular contractile function measured by global longitudinal strain improved at 50% compared with 100% TBF [-2.8 (-7.6- -0.1) vs. -1.2 (-5.2-0) %, p < 0.001]. Similarly, left ventricular ejection fraction increased [24.4 (15.8-35.5) vs. 16.7 (10.0-28.5) %, p < 0.001] and left ventricular outflow tract velocity time integral increased [7.7 (3.8-11.4) vs. 4.8 (2.5-8.5) cm, p < 0.001]. Adding echocardiographic parameters of left ventricular systolic function to the Survival After Veno-arterial ECMO (SAVE) score had better discriminatory value in predicting eventual hospital mortality (AUROC 0.69, 95% CI 0.55-0.84, p = 0.008) and successful weaning from V-A ECMO (AUROC 0.68, 95% CI 0.53-0.83, p = 0.017). Conclusion: In the initial period of V-A ECMO support, measures of left ventricular function including left ventricular ejection fraction and global longitudinal strain were inversely related to ECMO blood flow rate. Understanding the heart-ECMO interaction is vital to interpretation of echocardiographic measures of the left ventricle while on ECMO.

Feasibility of pump-controlled retrograde trial off in weaning from veno-arterial ECMO in adults: A single-center case series.

BACKGROUND: Various strategies of weaning V-A ECMO have been described. PCRTO is a weaning technique which involves serial decremental pump revolutions until a retrograde flow from the arterial to venous ECMO cannula is achieved. It has been reported as a feasible weaning strategy in the pediatric population, but its application in adults has not been widely reported. METHODS: This was a case series including all adult patients who underwent PCRTO during weaning from V-A ECMO at a tertiary ECMO center between January 2019 and July 2021. The primary end point was the successful weaning from V-A ECMO support. RESULTS: A total of 57 runs of PCRTO in 36 patients were analyzed-45 (78.9%) of the trials were concluded successfully. The median retrograde blood flow rate during PCRTO was 0.6 ± 0.2 L/min, and the median duration of each PCRTO was 180 (120-240) min. Of the 35 patients who had at least one session of successful PCRTO, 31 (88.6%) were ultimately weaned from ECMO. There were no major complications from PCRTO including systemic or circuit thrombosis. CONCLUSIONS: PCRTO is a feasible strategy for assessing readiness for weaning from V-A ECMO with a low risk of adverse events and high rate of predicting eventual successful ECMO decannulation. Further investigation including comparison with alternative weaning strategies in prospective studies is required to confirm the approach.

Starting and Sustaining an Extracorporeal Membrane Oxygenation Program.

The use of extracorporeal membrane oxygenation (ECMO) is growing rapidly in all patient populations, especially adults for both acute lung or heart failure. ECMO is a complex, high risk, resource-intense, expensive modality that requires appropriate planning, training, and management for successful outcomes. This article provides an optimal approach and the basic framework for initiating a new ECMO program, which can be tailored to meet local needs. Setting up a new ECMO program and sustaining it requires institutional commitment, physician champions, multidisciplinary team involvement, ongoing training, and education of the ECMO team personnel and a robust quality assurance program to minimize complications and improve outcomes.

Restrictive and liberal transfusion strategies in extracorporeal membrane oxygenation: A retrospective observational study.

BACKGROUND: To compare the outcomes of patients requiring extracorporeal membrane oxygenation (ECMO) support who had a restrictive transfusion strategy with those who had a liberal strategy. STUDY DESIGN AND METHODS: We retrospectively reviewed all adult patients from 2010 to 2019 who received a minimum of one packed red blood cell (pRBC) during ECMO. Hemoglobin values before each transfusion were retrieved. Restrictive transfusion strategy was defined as a transfusion threshold ≤8.5 g/dl in all transfusion episodes for a single patient, while liberal transfusion strategy was defined as a transfusion threshold >8.5 g/dl in any transfusion episode. RESULTS: The analysis included 763 patients, with 138 (18.1%) patients in the restrictive and 625 (81.9%) in the liberal transfusion strategy group. The median hemoglobin level, taking into account all measured hemoglobin values, during ECMO support was 8.3 and 9.9 g/dl, and the average units of pRBC received per day were 0.7 (0.3-1.8) and 1.2 (0.6-2.3), respectively. There were no significant differences in intensive care unit (ICU) mortality (adjusted odds ratio (OR), 0.86; 95% CI 0.56-1.30; p = .47), hospital mortality (adjusted OR, 0.79; 95% CI 0.52-1.21; p = .28), and 90-day mortality (adjusted OR, 0.84; 95% CI 0.55-1.28; p = .42) between the two groups. Among subgroup analyses, a restrictive transfusion strategy was associated with decreased risk of ICU mortality in patients on veno-venous ECMO (adjusted OR, 0.36; 95% CI 0.17-0.73; p = .005). There was no heterogeneity on outcomes across patients stratified by age, APACHE IV score, or need for large volume transfusion. DISCUSSION: Our data suggested it may be safe to adopt a restrictive red cell transfusion threshold of 8.5 g/dl in patients on ECMO, and highlighted the need for prospective trials in this heavily-transfused population.

Identification of Diverse Stress-Responsive Xylem Sap Peptides in Soybean.

Increasing evidence has revealed that plant secretory peptides are involved in the long-distance signaling pathways that help to regulate plant development and signal stress responses. In this study, we purified small peptides from soybean (Glycine max) xylem sap via o-chlorophenol extraction and conducted an in-depth peptidomic analysis using a mass spectrometry (MS) and bioinformatics approach. We successfully identified 14 post-translationally modified peptide groups belonging to the peptide families CEP (C-terminally encoded peptides), CLE (CLAVATA3/embryo surrounding region-related), PSY (plant peptides containing tyrosine sulfation), and XAP (xylem sap-associated peptides). Quantitative PCR (qPCR) analysis showed unique tissue expression patterns among the peptide-encoding genes. Further qPCR analysis of some of the peptide-encoding genes showed differential stress-response profiles toward various abiotic stress factors. Targeted MS-based quantification of the nitrogen deficiency-responsive peptides, GmXAP6a and GmCEP-XSP1, demonstrated upregulation of peptide translocation in xylem sap under nitrogen-deficiency stress. Quantitative proteomic analysis of GmCEP-XSP1 overexpression in hairy soybean roots revealed that GmCEP-XSP1 significantly impacts stress response-related proteins. This study provides new insights that root-to-shoot peptide signaling plays important roles in regulating plant stress-response mechanisms.

Sensitivity of ventricular systolic function to afterload during veno-arterial extracorporeal membrane oxygenation.

AIMS: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) increases afterload to the injured heart and may hinder myocardial recovery. We aimed to compare the sensitivity of left ventricular (LV) systolic function to the afterload effects of peripheral V-A ECMO during the acute and delayed stages of acute myocardial dysfunction. METHODS AND RESULTS: A total of 46 adult patients who were supported by peripheral V-A ECMO between April 2019 and June 2021 were analysed. Serial cardiac performance parameters were measured by transthoracic echocardiography (TTE) on mean day 1 ± 1 of V-A ECMO initiation (n = 45, 'acute phase') and mean day 4 ± 2 of V-A ECMO initiation (n = 36, 'delayed phase'). Measurements were obtained at 100%, 120%, and 50% of ECMO target blood flow (TBF). LV global longitudinal strain (GLS) significantly improved from -6.1 (-8.9 to -4.0)% during 120% TBF to -8.8 (-11.5 to -6.0)% during 50% TBF (P < 0.001). The sensitivity of LV GLS to changes in ECMO flow was significantly greater in the acute phase of myocardial injury compared with the delayed phase [median (IQR) percentage change: 72.7 (26.8-100.0)% vs. 22.5 (14.9-43.8)%, P < 0.001]. Findings from other echocardiographic parameters including LV ejection fraction [43.0 (29.1-56.8)% vs. 22.8 (9.2-42.2)%, P = 0.012] and LV outflow tract velocity-time integral [45.8 (18.6-58.7)% vs. 24.2 (12.6-34.0)%, P = 0.001] were similar. A total of 24 (52.2%) patients were weaned off ECMO successfully. CONCLUSIONS: We demonstrated that LV systolic function was significantly more sensitive to the afterload effects of V-A ECMO during the acute stage of myocardial dysfunction compared with the delayed phase. Understanding the evolution of the heart-ECMO interaction over the course of acute myocardial dysfunction informs the clinical utility of echocardiographic assessment in patients on V-A ECMO.

Effect of hospital case volume on clinical outcomes of patients requiring extracorporeal membrane oxygenation: a territory-wide longitudinal observational study.

Background: The utilization of extracorporeal membrane oxygenation (ECMO) has increased rapidly around the world. Being an overall low-volume high-cost form of therapy, the effectiveness of having care delivered in segregated units across a geographical locality is debatable. Methods: All adult extracorporeal membrane oxygenation cases admitted to public hospitals in Hong Kong between 2010 and 2019 were included. "High-volume" centers were defined as those with >20 extracorporeal membrane oxygenation cases in the respective calendar year, while "low-volume" centers were those with ≤20. Clinical outcomes of patients who received extracorporeal membrane oxygenation care in high-volume centers were compared with those in low-volume centers. Results: A total of 911 patients received extracorporeal membrane oxygenation-297 (32.6%) veno-arterial extracorporeal membrane oxygenation, 450 (49.4%) veno-venous extracorporeal membrane oxygenation, and 164 (18.0%) extracorporeal membrane oxygenation-cardiopulmonary resuscitation. The overall hospital mortality was 456 (50.1%). The annual number of extracorporeal membrane oxygenation cases in high- and low-volume centers were 29 and 11, respectively. Management in a high-volume center was not significantly associated with hospital mortality (adjusted odds ratio (OR) 0.86, 95% confidence interval (CI): 0.61-1.21, P=0.38), or with intensive care unit mortality (adjusted OR 0.76, 95% CI: 0.54-1.06, P=0.10) compared with a low-volume center. Over the 10-year period, the overall observed mortality was similar to the Acute Physiology And Chronic Health Evaluation IV-predicted mortality, with no significant difference in the standardized mortality ratios between high- and low-volume centers (P=0.46). Conclusions: In a territory-wide observational study, we observed that case volumes in extracorporeal membrane oxygenation centers were not associated with hospital mortality. Maintaining standards of care in low-volume centers is important and improves preparedness for surges in demand.

Predictors of Favorable Neurologic Outcomes in a Territory-First Extracorporeal Cardiopulmonary Resuscitation Program.

Extracorporeal cardiopulmonary resuscitation (ECPR) is an advanced resuscitation method that has been associated with better outcomes after cardiac arrest compared with conventional cardiopulmonary resuscitation. This is a retrospective analysis of all patients who received ECPR for cardiac arrest in Hong Kong's first ECPR program from 2012 to 2020. The primary outcome was favorable neurologic outcome at 3 months. A new risk prediction model was developed and its performance was compared with published risk scores. One-hundred two patients received ECPR and 19 (18.6%) patients survived with favorable neurologic outcome. Having a shockable rhythm was the strongest predictor of favorable neurologic outcome in multivariate analysis (odds ratio, 9.64; 95% confidence interval [CI], 1.49 to 62.30; P = 0.017). We developed a simple model with three parameters for the prediction of favorable neurologic outcomes - presence of shockable rhythm, mean arterial pressure after extracorporeal membrane oxygenation, and the Acute Physiology And Chronic Health Evaluation IV score, with an area under receiver operating characteristic curve of 0.85 (95% CI, 0.77 to 0.94). In Hong Kong's first ECPR program, 18.6% patients survived with favorable neurologic outcomes, and having a shockable rhythm at presentation was the strongest predictor. Risk scores are useful in predicting important patient outcomes and should be included in clinical decision-making for patients who received ECPR.

Comparison of the Efficiency and Usability of Aerosol Box and Intubation Tent on Intubation of a Manikin Using Personal Protective Equipment: A Randomized Crossover Study.

BACKGROUND: The aerosol box and intubation tent are improvised barrier-enclosure devices developed during the novel coronavirus pandemic to protect health care workers from aerosol transmission. OBJECTIVE: Using time to intubation as a crude proxy, we aimed to compare the efficiency and usability of the aerosol box and intubation tent in a simulated manikin. METHODS: This was a single-center, randomized, crossover manikin study involving 28 participants (9 anesthetists, 16 emergency physicians, and 3 intensivists). Each participant performed rapid sequence intubations in a random sequence of three different scenarios: 1) no device use; 2) aerosol box; 3) intubation tent. We compared the time to intubation between different scenarios. RESULTS: The median total intubation time with no device use, aerosol box, and intubation tent were 23.7 s (interquartile range [IQR] 19.4-28.4 s), 30.9 s (IQR 24.1-52.5 s), and 26.0 s (IQR 22.1-30.8 s), respectively. Post hoc analysis showed a significantly longer intubation time using the aerosol box compared with no device use (p < 0.001) and compared with the intubation tent (p < 0.001). The difference between the intubation tent and no device use was not significant. The first-pass intubation success rate did not differ between the groups. Only aerosol box use had resulted in breaches of personal protective equipment. Participants considered intubation with the intubation tent more favorable than the aerosol box. CONCLUSIONS: The intubation tent seems to have a better barrier-enclosure design than the aerosol box, with a reasonable balance between efficiency and usability. Further evaluation of its efficacy in preventing aerosol dispersal and in human studies are warranted prior to recommendation of widespread adoption.

Bicaval dual lumen cannula in adult veno-venous extracorporeal membrane oxygenation-clinical pearls for safe cannulation.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been traditionally delivered with two independent cannulae at different venous insertion sites. The bicaval dual lumen cannula has gained popularity as a cannula for simultaneous venous drainage and reinfusion of blood via the internal jugular vein (IJV). Its insertion requires special attention to details to prevent the occurrence of serious complications. In this review, we discuss different techniques of cannula insertion and tips for troubleshooting.

PostOperative ST-segment elevation: not a blocked coronary artery, then what?

ST-segment elevation is well known for its diagnostic value for transmural myocardial infarction due to acute thrombotic occlusion of a coronary artery, and often requires emergency reperfusion therapy. However, ST segment is by no means pathognomonic for acute coronary events. Here, we report a case of ST-segment elevation after hepatectomy secondary to an unusual etiology.

Complication of venovenous extracorporeal membrane oxygenation cannulation - the significance of an inferior vena cava anomaly.

Physicians should be aware of possible anatomical variants during cannulation for extracorporeal membrane oxygenation (ECMO). Particular attention to ensure continual visualization of the guidewire before proceeding to final positioning of the ECMO cannulae should be paid. Alternative imaging modalities should be contemplated when uncertainties arise to minimize the risk of inadvertent vascular injuries.

Speckle tracking echocardiography in patients with septic shock: a case control study (SPECKSS).

BACKGROUND: Sepsis-induced myocardial dysfunction is a well-recognized condition and confers worse outcomes in septic patients. Echocardiographic assessment by conventional parameters such as left ventricular ejection fraction (LVEF) is often affected by ongoing changes in preload and afterload conditions. Novel echocardiographic technologies such as speckle tracking echocardiography (STE) have evolved for direct assessment of the myocardial function. We investigate the measurement of myocardial strain by speckle tracking echocardiography for the diagnosis of sepsis-induced myocardial dysfunction. METHODS: This is a case-control study at a university-affiliated medical intensive care unit. Consecutive adult medical patients admitted with a diagnosis of septic shock were included. Patients with other causes of myocardial dysfunction were excluded. They were compared to age-matched, gender-matched, and cardiovascular risk-factor-matched controls, who were admitted to hospital for sepsis but did not develop septic shock. Transthoracic echocardiography was performed on all patients within 24 hours of diagnosis, and a reassessment echocardiogram was performed in the study group of patients upon recovery. RESULTS: Patients with septic shock (n = 33) (study group) and 29 matched patients with sepsis but no septic shock (control group) were recruited. The mean sequential organ failure assessment (SOFA) score for the study and control groups were 10.2 and 1.6, respectively (P < 0.001). In patients with septic shock, the mean arterial pressure was lower (76 mmHg vs 82 mmHg, P = 0.032), and the heart rate was higher (99 bpm vs 86 bpm, P = 0.008). The cardiac output (5.9 L/min vs 5.5 L/min, P = 0.401) and systemic vascular resistance (1090 dynes•sec/cm(5) vs 1194 dynes•sec/cm(5), P = 0.303) were similar. The study group had a greater degree of myocardial dysfunction measured by global longitudinal strain (GLS) (-14.5 % vs -18.3 %, P <0.001), and the myocardial strain differed upon diagnosis and recovery (-14.5 % vs -16.0 %, P = 0.010). Conventional echocardiographic measurements such as LVEF (59 % in the study group vs 61 % in the control group, P = 0.169) did not differ between the two groups. CONCLUSION: Speckle tracking echocardiography can detect significant left ventricular impairment in patients with septic shock, which was not otherwise detectable by conventional echocardiography. The reversible nature of myocardial dysfunction in sepsis was also demonstrable. This echocardiographic technique is useful in the diagnosis and monitoring of sepsis-induced myocardial dysfunction.

A detailed evaluation of cardiac function in cirrhotic patients and its alteration with or without liver transplantation.

BACKGROUND: Cirrhosis has been shown to be associated with left ventricular (LV) myocardial dysfunction, but studies of right ventricular (RV) function in cirrhotic patients compared with controls are scarce. Limited studies have prospectively evaluated the progression of myocardial function in patients with cirrhosis and assessed changes in cardiac function following liver transplantation (LTx). So the aim of the study was to evaluate biventricular myocardial function in cirrhotic patients and its alteration with or without liver transplantation. METHODS: A total of 103 patients with cirrhosis (age 55±7 years, male 75%) were recruited. Conventional and 2-dimensional speckle tracking echocardiography was performed to determine the presence of LV and RV (biventricular) dysfunction. For comparison, 48 matched control subjects were included. Follow-up echocardiography was performed in 41 patients following LTx and in 26 patients who did not undergo LTx. RESULTS: Patients with cirrhosis had biventricular dilatation, increased LV mass, impaired LV diastolic function, and biventricular systolic strain compared with controls. Following LTx, cirrhotic patients had reduced biventricular dilatation, a smaller LV mass, and improved biventricular systolic strain after a mean duration of 18.2±6.6 months. Patients who did not undergo LTx had a further increase in LV mass but no significant change in biventricular dimensions or systolic strain (mean duration of 20.4±8.3 months). CONCLUSIONS: The present study demonstrates that patients with cirrhosis had biventricular dilatation and impaired biventricular systolic strain compared with controls. Following LTx, biventricular dilatation reduced and biventricular systolic strain improved. In contrast, patients who did not undergo LTx experienced a further increase in LV mass.