Disease-associated mutations in Drp1 have fundamentally different effects on the mitochondrial fission machinery.

Patient mutations have been identified throughout dynamin-related protein 1 (Drp1), the key protein mediator of mitochondrial fission. These changes generally impact young children and often result in severe neurological defects and, in some instances, death. Until now, the underlying functional defect leading to patient phenotypes has been largely speculative. We therefore analyzed six disease-associated mutations throughout the GTPase and middle domains (MD) of Drp1. The MD plays a role in Drp1 oligomerization, and three mutations in this region were predictably impaired in self-assembly. However, another mutant in this region (F370C) retained oligomerization capability on pre-curved membranes despite being assembly-limited in solution. Instead, this mutation impaired membrane remodeling of liposomes, which highlights the importance of Drp1 in generating local membrane curvature before fission. Two GTPase domain mutations were also observed in different patients. The G32A mutation was impaired in GTP hydrolysis both in solution and in the presence of lipid but remains capable of self-assembly on these lipid templates. The G223V mutation also exhibited decreased GTPase activity and was able to assemble on pre-curved lipid templates; however, this change impaired membrane remodeling of unilamellar liposomes similar to F370C. This demonstrates that the Drp1 GTPase domain also contributes to self-assembly interactions that drive membrane curvature. Overall, the functional defects caused by mutations in Drp1 are highly variable even for mutations that reside within the same functional domain. This study provides a framework for characterizing additional Drp1 mutations to provide a comprehensive understanding of functional sites within this essential protein.

Renin Levels and Angiotensin II Responsiveness in Vasopressor-Dependent Hypotension.

OBJECTIVES: The relationship between renin levels, exposure to renin-angiotensin system (RAS) inhibitors, angiotensin II (ANGII) responsiveness, and outcome in patients with vasopressor-dependent vasodilatory hypotension is unknown. DESIGN: We conducted a single-center prospective observational study to explore whether recent RAS inhibitor exposure affected baseline renin levels, whether baseline renin levels predicted ANGII responsiveness, and whether renin levels at 24 hours were associated with clinical outcomes. SETTING: An academic ICU in Melbourne, VIC, Australia. PATIENTS: Forty critically ill adults who received ANGII as the primary agent for vasopressor-dependent vasodilatory hypotension who were included in the Acute Renal effects of Angiotensin II Management in Shock study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After multivariable adjustment, recent exposure to a RAS inhibitor was independently associated with a relative increase in baseline renin levels by 198% (95% CI, 36-552%). The peak amount of ANGII required to achieve target mean arterial pressure was independently associated with baseline renin level (increase by 46% per ten-fold increase; 95% CI, 8-98%). Higher renin levels at 24 hours after ANGII initiation were independently associated with fewer days alive and free of continuous renal replacement therapy (CRRT) (-7 d per ten-fold increase; 95% CI, -12 to -1). CONCLUSIONS: In patients with vasopressor-dependent vasodilatory hypotension, recent RAS inhibitor exposure was associated with higher baseline renin levels. Such higher renin levels were then associated with decreased ANGII responsiveness. Higher renin levels at 24 hours despite ANGII infusion were associated with fewer days alive and CRRT-free. These preliminary findings emphasize the importance of the RAS and the role of renin as a biomarker in patients with vasopressor-dependent vasodilatory hypotension.

Cognitive household labor: gender disparities and consequences for maternal mental health and wellbeing.

PURPOSE: Although the division of unpaid household labor has been studied as a driver of global gender inequity, the cognitive dimension of household labor-planning, anticipating, and delegating household tasks-has received less empirical investigation. Cognitive household labor represents a form of invisible and often unacknowledged domestic work that has been challenging to measure. METHODS: Within 322 mothers of young children, we assessed the division of both cognitive ("planning") and physical ("execution") household labor within 30 common household tasks using a self-report measure. RESULTS: We found that while mothers did more of the overall domestic labor than their partners, the division of cognitive labor was particularly gendered, such that women's share of cognitive labor was more disproportionate than physical household labor. We found that cognitive labor was associated with women's depression, stress, burnout, overall mental health, and relationship functioning. CONCLUSIONS: This study is one of the first to investigate cognitive labor quantitatively, and the first to investigate cognitive and physical dimensions within the same household tasks. Understanding how cognitive labor affects mothers' mental wellbeing has important implications for both practice and policy.

Guidewire-assisted cannulation of the common bile duct for the prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis.

BACKGROUND: Cannulation techniques have been recognized as being important in causing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, considerable controversy exists about the usefulness of the guidewire-assisted cannulation technique for the prevention of PEP. OBJECTIVES: To assess the effectiveness and safety of the guidewire-assisted cannulation technique compared to the conventional contrast-assisted cannulation technique for the prevention of PEP in people undergoing diagnostic or therapeutic ERCP for biliary or pancreatic diseases. SEARCH METHODS: For the previous version of this review, we searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL and major conference proceedings, up to February 2012, with no language restrictions. An updated search was performed on 26 February 2021 for the current version of this review. Two clinical trial registries, clinicaltrials.gov and WHO ICTRP, were also searched in this update. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing the guidewire-assisted cannulation technique versus the contrast-assisted cannulation technique in people undergoing ERCP. DATA COLLECTION AND ANALYSIS: Two review authors conducted study selection, data extraction, and methodological quality assessment independently. Using intention-to-treat analysis with random-effects models, we combined dichotomous data to obtain risk ratios (RR) with 95% confidence intervals (CI). We assessed heterogeneity using the Chi² test (P < 0.10) and I² statistic (> 50%). To explore sources of heterogeneity, we conducted a priori subgroup analyses according to trial design, publication type, risk of bias, use of precut sphincterotomy, inadvertent guidewire insertion or contrast injection of the pancreatic duct (PD), use of a PD stent, cannulation device, and trainee involvement in cannulation. To assess the robustness of our results, we carried out sensitivity analyses using different summary statistics (RR versus odds ratio (OR)) and meta-analytic models (fixed-effect versus random-effects) and per-protocol analysis. MAIN RESULTS: 15 RCTs comprising 4426 participants were included. There was moderate heterogeneity among trials for the outcome of PEP (P = 0.08, I² = 36%). Meta-analyses suggest that the guidewire-assisted cannulation technique probably reduces the risk of PEP compared to the contrast-assisted cannulation technique (RR 0.51, 95% CI 0.36 to 0.72, 15 studies, moderate-certainty evidence). In addition, the guidewire-assisted cannulation technique may result in an increase in primary cannulation success (RR 1.06, 95% CI 1.01 to 1.12, 13 studies, low-certainty evidence), and probably reduces the need for precut sphincterotomy (RR 0.79, 95% CI 0.64 to 0.96, 10 studies, moderate-certainty evidence). Compared to the contrast-assisted cannulation technique, the guidewire-assisted cannulation technique may result in little to no difference in the risk of post-sphincterotomy bleeding (RR 0.87, 95% CI 0.49 to 1.54, 7 studies, low-certainty evidence) and perforation (RR 0.93, 95% CI 0.11 to 8.23, 8 studies, very low-certainty evidence). Procedure-related mortality was reported by eight studies, and there were no cases of deaths in both arms (moderate-certainty evidence). Subgroup analyses suggest that the heterogeneity for the outcome of PEP could be explained by differences in trial design. The results were robust in sensitivity analyses. AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that the guidewire-assisted cannulation technique probably reduces the risk of PEP compared to the contrast-assisted cannulation technique. There is low-certainty evidence that the guidewire-assisted cannulation technique may result in an increase in primary cannulation success. There is low- and very low-certainty evidence that the guidewire-assisted cannulation technique may result in little to no difference in the risk of bleeding and perforation. No procedure-related deaths were reported. Therefore, the guidewire-assisted cannulation technique appears to be superior to the contrast-assisted cannulation technique considering the certainty of evidence and the balance of benefits and harms. However, the routine use of guidewires in biliary cannulation will be dependent on local expertise, availability, and cost. Future research should assess the effectiveness and safety of the guidewire-assisted cannulation technique in the context of other pharmacologic or non-pharmacologic interventions for the prevention of PEP.

Importance of the Immunodominant CD8+ T Cell Epitope of Plasmodium berghei Circumsporozoite Protein in Parasite- and Vaccine-Induced Protection.

The circumsporozoite protein (CSP) builds up the surface coat of sporozoites and is the leading malaria pre-erythrocytic-stage vaccine candidate. CSP has been shown to induce robust CD8+ T cell responses that are capable of eliminating developing parasites in hepatocytes, resulting in protective immunity. In this study, we characterized the importance of the immunodominant CSP-derived epitope SYIPSAEKI of Plasmodium berghei in both sporozoite- and vaccine-induced protection in murine infection models. In BALB/c mice, where SYIPSAEKI is efficiently presented in the context of the major histocompatibility complex class I (MHC-I) molecule H-2-Kd, we established that epitope-specific CD8+ T cell responses contribute to parasite killing following sporozoite immunization. Yet, sterile protection was achieved in the absence of this epitope, substantiating the concept that other antigens can be sufficient for parasite-induced protective immunity. Furthermore, we demonstrated that SYIPSAEKI-specific CD8+ T cell responses elicited by viral-vectored CSP-expressing vaccines effectively targeted parasites in hepatocytes. The resulting sterile protection strictly relied on the expression of SYIPSAEKI. In C57BL/6 mice, which are unable to present the immunodominant epitope, CSP-based vaccines did not confer complete protection, despite the induction of high levels of CSP-specific antibodies. These findings underscore the significance of CSP in protection against malaria pre-erythrocytic stages and demonstrate that a significant proportion of the protection against the parasite is mediated by CD8+ T cells specific for the immunodominant CSP-derived epitope.

Executive dysfunctions differentially predict amotivation in first-episode schizophrenia-spectrum disorder: a prospective 1-year follow-up study.

Amotivation is a major determinant of functional outcome in schizophrenia but it is understudied in the early course of illness. There is a paucity of longitudinal research investigating predictors of amotivation. In this study, we aimed to examine baseline cognitive and clinical predictors of amotivation at 6 and 12 months of follow-up in patients aged 18-55 years presenting with first-episode DSM-IV schizophrenia-spectrum disorder (FES). Of 145 patients recruited at intake, 116 and 113 completed assessments at 6- and 12-month follow-up, respectively. Amotivation was measured by avolition-apathy and anhedonia-asociality subscale scores of the Scale of the Assessment of Negative Symptoms. Cognitive assessment was administered at baseline. As executive dysfunction has been more consistently found to be associated with negative symptoms and amotivation in prior literature, we adopted fractionated approach to subdivide executive function into distinct components encompassing switching and flexibility, response initiation, response inhibition, planning and strategy allocation, sustained attention and working memory. Our results showed that baseline amotivation (p = 0.01) and switching and flexibility (p = 0.01) were found to independently predict amotivation at 6 months follow-up. Baseline amotivation (p < 0.01) and switching and flexibility (albeit with trend-wise significance, p = 0.06) were also retained in final multivariate regression model for 12-month amotivation prediction. No other executive components or cognitive domains predicted amotivation at follow-up. Findings of our study thus indicate amotivation at initial presentation as a critical determinant of subsequent motivational deficits over 1 year of treatment for FES patients. Cognitive flexibility might be specifically related to the development of amotivation in the early stage of illness.

Using operating room turnover time by anesthesia trainee level to assess improving systems-based practice milestones.

BACKGROUND: Operating room (OR) metrics are frequently cited when optimizing cost efficacy and quality of care (Weiss et al, Characteristics of operating room procedures in U.S. hospitals, 2011: Statistical brief #170, 2013; Macario A, Anesthesiology 105:237-240, 2006; Childers et al, JAMA Surg 153:e176233, 2018). Little has been reported to evaluate how anesthesia trainees change anesthesia-related efficiencies in the OR. Statistical correlation may demonstrate awareness and implementation of efficient systems-based practice. METHODS: Utilizing computerized OR information systems, specific data regarding anesthesia controlled turnover times were collected (546 data points) over the course of 4 months. The type of surgery performed, patient's American Society of Anesthesiologists (ASA) physical status and OR turnover times were compared for clinical anesthesia (CA) trainee levels CA1, CA2, CA3 and CRNAs. Standard descriptive statistics were computed. Analysis of variance (ANOVA) was performed to compare the average turnover time. RESULTS: Average OR turnover time was 31 min ranging from 8 to 60 min. There was a significant difference between the OR turnover time of CA-1 (32 min) compared to CA-3 (29 min) (p = 0.017) and CA-1 compared to CRNA (30 min) (p = 0.016). OR turnover time was significantly shorter in CA-3 and CRNA. The analysis showed no differences between OR turnover time of ASA categories. CONCLUSIONS: These findings posit that trainees improve efficiency over time, but that education may for a time come at the expense of productivity. This trend may demonstrate a more profound understanding and mastery of a learner progressing in the graduate medical education system. This interplay plays a key role in clinical and academic shared success.

Adaptive steroid tapering impedes corticosteroid-free remissions compared to forced tapering in clinical trials of ulcerative colitis.

INTRODUCTION: It is unclear if steroid tapering protocols can impact clinical trial outcomes in ulcerative colitis (UC), particularly fixed versus adaptive steroid tapering. Fixed steroid tapering involves incremental dose decreases at prespecified intervals and adaptive steroid tapering utilizes investigator discretion as determined by the patient's response. METHODS: In this post-hoc analysis from six clinical trials of UC (VARSITY, ACT 1, PURSUIT, GEMINI1, OCTAVE and ULTRA2), responders to induction therapy with baseline corticosteroid use were considered as the primary population of interest. Adjustments were made to account for treat-through versus re-randomization designs and multivariate regression was performed to account for other potential confounding variables. The primary outcome was corticosteroid-free clinical remission (CR) at one-year and secondary outcomes were CR and endoscopic improvement. RESULTS: There was a total of 861 patients who had achieved clinical response after induction and were using corticosteroids. Within multivariate analysis, patients using adaptive steroid tapering regimens were less likely to achieve corticosteroid-free CR at one year (odds ratio [OR] 0.66 [95% CI 0.48-0.92], p=0.015) but had increased odds for achieving CR at one year (OR 1.9 [95% CI 1.43-2.52], p<0.001). The steroid tapering regimen was not associated with achievement of endoscopic improvement at one year. CONCLUSIONS: Among patients with UC on corticosteroids in clinical trials, patients using adaptive steroid weaning regimens were less likely to achieve corticosteroid-free CR at one year but more likely to achieve CR at one year. Consideration should be given to implementing mandatory fixed steroid weaning protocols in future clinical trials of UC.

Exploring the norepinephrine to angiotensin II conversion ratio in patients with vasodilatory hypotension: A post-hoc analysis of the ARAMIS trial.

PURPOSE: Angiotensin II is approved for catecholamine-refractory vasodilatory shock but the conversion dose ratio from norepinephrine to angiotensin II remains unclear. METHODS: We conducted a post-hoc analysis of the Acute Renal effects of Angiotensin II Management in Shock (ARAMIS) trial involving patients with vasodilatory hypotension. We determined the norepinephrine equivalent dose immediately prior to angiotensin II initiation and calculated the conversion dose ratio between norepinephrine and angiotensin II. We performed subgroup analyses based on recent exposure to angiotensin receptor blockers (ARBs) and renin levels at baseline. RESULTS: In 37 patients, the median conversion dose ratio between norepinephrine equivalent and angiotensin II was to 10:1 for norepinephrine bitartrate (5:1 for norepinephrine base). The conversion ratio was not affected by the baseline renin, with a median ratio of 10 (7-21) in the high renin group versus 12 (5-22) in the low renin group. Finally, exposure to ARBs prior admission appeared to diminish the conversion ratio with a median ratio of 7 (4-13) in ARB patients vs. 12 (7-22) in non-ARB patients. CONCLUSIONS: The norepinephrine to angiotensin II conversion dose ratio is 10:1 in a vasodilatory hypotension population. These findings can guide clinicians and researchers in the use, dosing, and study of angiotensin II in critical care.

A PILOT STUDY OF ANGIOTENSIN II AS PRIMARY VASOPRESSOR IN CRITICALLY ILL ADULTS WITH VASODILATORY HYPOTENSION: THE ARAMIS STUDY.

ABSTRACT: Objective: The aim of the study is to evaluate the efficacy and safety of using angiotensin II (Ang2) as primary vasopressor for vasodilatory hypotension. Methods: This was a prospective observational study of critically ill adults admitted to an academic intensive care unit (ICU) with vasodilatory hypotension. We treated 40 patients with Ang2 as primary vasopressor and compared them with 80 matched controls who received conventional vasopressors (norepinephrine, vasopressin, metaraminol, epinephrine, or combinations). Results : Mean age was 63 years and median Acute Physiology and Chronic Health Evaluation III score was 65. Ang2 patients had lower ICU mortality (10% vs 26%, P = 0.04); however, their 28- and 90-day mortality was not significantly different (18% vs 29%, P = 0.18; 22% vs 30%, P = 0.39). Peak serum creatinine levels were similar (128 vs 126 µmol/L, P = 0.81), as was the incidence and stage of acute kidney injury (70% vs 74%, P = 0.66), requirement for continuous renal replacement therapy (14% vs 13%, P = 0.84), and risk of major adverse kidney events at 7 days (20% vs 29%, P = 0.30). However, Ang2 patients with prior exposure to renin angiotensin aldosterone system inhibitors had a lower peak serum creatinine ( P = 0.03 for interaction) than conventional vasopressors patients, and serum troponin elevations were less common with Ang2 (8% vs 22%, P = 0.04). The incidence of thromboembolic complications was similar. Conclusions: Primary Ang2 administration in vasodilatory hypotension did not seem harmful compared with conventional vasopressors. Although Ang2 did not decrease peak serum creatinine levels or major adverse kidney events, its effects on intensive care unit survival, serum troponin, and renal function in patients on renin angiotensin aldosterone system inhibitors warrant further exploration in randomized trials (ACTRN12621000281897).

Arabidopsis histidine kinase 5 regulates salt sensitivity and resistance against bacterial and fungal infection.

• The ability of plants to adapt to multiple stresses imposed by the natural environment requires cross-talk and fine-tuning of stress signalling pathways. The hybrid histidine kinase Arabidopsis histidine kinase 5 (AHK5) is known to mediate stomatal responses to exogenous and endogenous signals in Arabidopsis thaliana. The purpose of this study was to determine whether the function of AHK5 in stress signalling extends beyond stomatal responses. • Plant growth responses to abiotic stresses, tissue susceptibility to bacterial and fungal pathogens, and hormone production and metabolism of reactive oxygen species were monitored in a T-DNA insertion mutant of AHK5. • The findings of this study indicate that AHK5 positively regulates salt sensitivity and contributes to resistance to the bacterium Pseudomonas syringae pv. tomato DC3000 and the fungal pathogen Botrytis cinerea. • This is the first report of a role for AHK5 in the regulation of survival following challenge by a hemi-biotrophic bacterium and a necrotrophic fungus, as well as in the growth response to salt stress. The function of AHK5 in regulating the production of hormones and redox homeostasis is discussed.

MONitoring Knockbacks in EmergencY (MONKEY) - An Audit of Disposition Outcomes in Emergency Patients with Rejected Admission Requests.

Background: Emergency Department (ED) clinicians commonly experience difficulties in referring patients to inpatient teams for hospital admission. There is limited literature reporting on patient outcomes following these complicated referrals, where ED requests for inpatient admission are rejected - which study investigators termed a "knockback". Purpose: To identify disposition outcomes and referral accuracy in ED patients whose admission referral was initially rejected. Secondary objectives were to identify additional patient, clinician and systemic factors associated with knockbacks. Selection and Methodology: Emergency clinicians prospectively nominated a convenience sample of patients identified as having knockbacks over two time periods (Jan-Feb 2020 and Aug 2020 to Jan 2021) at a tertiary Australian ED. Data were analyzed with a mixed-methods approach and subsequent descriptive and thematic analyses were performed. Results: A total of 109 patients were identified as knockbacks. The referrals were warranted, with 89.0% of cases (n = 97) ultimately requiring a hospital admission. In 60.6% (n = 66) of the admissions, patients were admitted under the inpatient team initially referred to by the ED, suggesting referrals were generally accurate. The number of in-hospital units involved in the admission process and ED length of stay were positively correlated (0.409, p < 0.001). Patient factors associated with knockbacks include pre-existing chronic medical conditions and presenting acutely unwell. Analysis of clinicians' perspectives yielded recurring themes of disagreements over admission destination and diagnostic uncertainty. Conclusion: In this patient sample, emergency referrals for admission were mostly warranted and accurate. Knockbacks increase ED length of stay and may adversely affect patient care. Further focused discussion and clearer referral guidelines between ED clinicians and their inpatient colleagues are required.

Acute Flare of Adult-Onset Autoimmune Enteropathy Associated With Cyclophosphamide.

This is a case of adult-onset autoimmune enteropathy (AIE) in a 46-year-old man with multiple autoimmune conditions who presented with worsening disease process after receiving cyclophosphamide. We describe the investigations and management of this patient over a 6-year timeline. The diagnosis and management of AIE is challenging given the heterogeneity in clinicopathologic findings and a small number of adult case reports. We describe the current diagnostic criteria, review the literature on treatment options and outcomes, and discuss the evidence for cyclophosphamide in the treatment of AIE. Adult-onset AIE should be considered in the differential diagnosis of refractory diarrhea and weight loss.

[Corrigendum] Blocking the Nav1.5 channel using eicosapentaenoic acid reduces migration and proliferation of ovarian cancer cells.

Following the publication of this article, the authors regret that they did not make it clear which author was funded by the funding bodies. The information in the "Funding" part of the paper should therefore have been written as shown in follows (changes to the original text are highlighted in bold): "The present study was supported by the Young Scientists Fund of the National Natural Science, Foundation of China (to JL; grant no. 81502226) and the Guangdong Natural Science Foundation (to JL; grant no. 2014A030313038)." The authors apologize to the readership of the Journal for any inconvenience caused. [the original article was published in International Journal of Oncology 53: 855­865, 2018; DOI: 10.3892/ijo.2018.4437].

Blocking the Nav1.5 channel using eicosapentaenoic acid reduces migration and proliferation of ovarian cancer cells.

Activity of the voltage-gated Nav1.5 sodium channel has been reported to be involved in cell proliferation, cancer invasion and gene expression. In addition, eicosapentaenoic acid (EPA) has recently been suggested to inhibit ovarian cancer cell growth and suppress tumor metastasis. The present study aimed to explore the association between EPA, the Nav1.5 sodium channel and ovarian cancer cells. Using patch-clamp technique and RNA interference approaches, sodium currents were recorded in epithelial ovarian cancer cells, and it was confirmed that the Nav1.5 channel carried the sodium currents. Furthermore, EPA effectively inhibited sodium currents in a dose-dependent manner, shifted the steady-state inactivation curve of sodium currents to the hyperpolarizing direction and reduced sodium window currents. In addition, EPA induced a shift in the inactivation curve in a dose-dependent manner. Inhibition of the sodium channel, either by EPA or by Nav1.5 knockdown, attenuated ovarian cancer cell migration and proliferation. To the best of our knowledge, the present study is the first to conduct sodium current recording in ovarian cancer cells, and revealed that EPA may inhibit Nav1.5-mediated ovarian cancer cell migration and growth. These findings not only present a potential prognostic biomarker for ovarian cancer, but also provide a strategy towards the development of novel pharmacological treatments for patients with ovarian cancer.