The patterned assembly and stepwise Vps4-mediated disassembly of composite ESCRT-III polymers drives archaeal cell division

ESCRT-III family proteins form composite polymers that deform and cut membrane tubes in the context of a wide range of cell biological processes across the tree of life. In reconstituted systems, sequential changes in the composition of ESCRT-III polymers induced by the AAA-adenosine triphosphatase Vps4 have been shown to remodel membranes. However, it is not known how composite ESCRT-III polymers are organized and remodeled in space and time in a cellular context. Taking advantage of the relative simplicity of the ESCRT-III-dependent division system in Sulfolobus acidocaldarius, one of the closest experimentally tractable prokaryotic relatives of eukaryotes, we use super-resolution microscopy, electron microscopy, and computational modeling to show how CdvB/CdvB1/CdvB2 proteins form a precisely patterned composite ESCRT-III division ring, which undergoes stepwise Vps4-dependent disassembly and contracts to cut cells into two. These observations lead us to suggest sequential changes in a patterned composite polymer as a general mechanism of ESCRT-III-dependent membrane remodeling. </p

ifo Konjunkturprognose 2011: Aufschwung setzt sich verlangsamt fort

Am 14. Dezember 2010 stellte das ifo Institut im Rahmen seines vorweihnachtlichen Pressegesprächs seine Prognose für die Jahre 2010 und 2011 vor. Die deutsche Wirtschaft hat ihren vor mehr als einem Jahr begonnenen Aufholprozess mit hoher Dynamik fortgesetzt. Nachdem die Impulse dafür zunächst aus dem Ausland gekommen waren, gewann die Binnenwirtschaft in den vergangenen drei Quartalen mehr und mehr an Bedeutung. Besonders wichtig war dafür der Investitionsanreiz, der aus einem historisch niedrigen Zinsniveau resultierte. Die gesamtwirtschaftliche Produktion, getrieben vom kräftig expandierenden industriellen Kern, dürfte im Jahresendquartal 2010 saison- und kalenderbereinigt leicht beschleunigt um 0,8% zugenommen haben. Im Jahresdurchschnitt 2010 expandiert das reale Bruttoinlandsprodukt damit um 3,7%. Im kommenden Jahr bleiben die Konjunkturampeln in Deutschland auf Grün, das Bruttoinlandsprodukt dürfte - bei einem 67%-Unsicherheitsintervall von 1,4 bis 3,4% - um 2,4% steigen. Entscheidend hierfür wird voraussichtlich die Entwicklung der heimischen Nachfrage sein. Bei alledem ist zu erwarten, dass sich die Beschäftigungssituation weiter verbessert. Nachdem die Unternehmen des verarbeitenden Gewerbes in diesem Jahr überwiegend Leiharbeiter eingestellt haben, dürften im kommenden Jahr auch die Stammbelegschaften ausgeweitet werden. Auch werden wohl wieder vermehrt sozialversicherungspflichtige Vollzeitstellen geschaffen. Die Arbeitslosenquote dürfte auf 7,0% sinken. Im Gefolge des Aufschwungs werden die Verbraucherpreise etwas anziehen, mit voraussichtlich 1,7% wird die Inflationsrate aber unter dem Preisziel der EZB bleiben. Das staatliche Budgetdefizit, das im laufenden Jahr in Relation zum nominalen Bruttoinlandsprodukt 3,5% beträgt, wird im nächsten Jahr aufgrund der anhaltend guten Konjunktur, der Konsolidierungsmaßnahmen im Rahmen des Zukunftspakets und der Sparmaßnahmen in der gesetzlichen Krankenversicherung auf 2,3% sinken.

Efficacy and safety of Vilobelimab (IFX-1), a novel monoclonal anti-C5a antibody, in patients with early severe sepsis or septic shock — a randomized, placebo-controlled, double-blind, multicenter, phase IIa Trial (SCIENS Study)

IMPORTANCE:. Anaphylatoxin C5a, a proinflammatory complement split product, plays a central role in mediating organ dysfunction. OBJECTIVES:. This phase II clinical trial was conducted to study safety, tolerability, pharmacokinetics, and pharmacodynamics of vilobelimab, a recombinant monoclonal antibody against C5a, in patients with severe sepsis or septic shock. DESIGN:. Multicenter, randomized, and placebo-controlled study. SETTING AND PARTICIPANTS:. Eleven multidisciplinary ICUs across Germany. Adult patients with severe sepsis or septic shock and with early onset of infection-associated organ dysfunction. MAIN OUTCOMES AND MEASURES:. Patients were randomly assigned in a ratio of 2:1 to three subsequent dosing cohorts for IV vilobelimab or placebo receiving either 2 × 2 mg/kg (0 and 12 hr), 2 × 4 mg/kg (0 and 24 hr), and 3 × 4 mg/kg (0, 24, and 72 hr). Co-primary endpoints were pharmacodynamics (assessed by C5a concentrations), pharmacokinetics (assessed by vilobelimab concentrations), and safety of vilobelimab. Preliminary efficacy was evaluated by secondary objectives. RESULTS:. Seventy-two patients were randomized (16 patients for each vilobelimab dosing cohort and eight patients for each placebo dosing cohort). Vilobelimab application was associated with dosing dependent decrease in C5a compared with baseline (p < 0.001). Duration of C5a decrease increased with more frequent dosing. Membrane attack complex lysis capacity measured by 50% hemolytic complement was not affected. Vilobelimab was well tolerated with similar safety findings in all dose cohorts. No vilobelimab-specific adverse events emerged. For vilobelimab-treated patients, investigators attributed less treatment-emergent adverse events as related compared with placebo. Dosing cohorts 2 and 3 had the highest ICU-free and ventilator-free days. There was no difference in mortality, vasopressor-free days, or renal replacement therapy-free days between the groups. CONCLUSIONS AND RELEVANCE:. Administration of vilobelimab in patients with severe sepsis and septic shock selectively neutralizes C5a in a dose-dependent manner without blocking formation of the membrane attack complex and without resulting in detected safety issues. The data warrant further investigation of C5a inhibition in sepsis

Personalized medicine with IgGAM compared with standard of care for treatment of peritonitis after infectious source control (the PEPPER trial): study protocol for a randomized controlled trial

Background: Peritonitis is responsible for thousands of deaths annually in Germany alone. Even source control (SC) and antibiotic treatment often fail to prevent severe sepsis or septic shock, and this situation has hardly improved in the past two decades. Most experimental immunomodulatory therapeutics for sepsis have been aimed at blocking or dampening a specific pro-inflammatory immunological mediator. However, the patient collective is large and heterogeneous. There are therefore grounds for investigating the possibility of developing personalized therapies by classifying patients into groups according to biomarkers. This study aims to combine an assessment of the efficacy of treatment with a preparation of human immunoglobulins G, A, and M (IgGAM) with individual status of various biomarkers (immunoglobulin level, procalcitonin, interleukin 6, antigen D-related human leucocyte antigen (HLA-DR), transcription factor NF-κB1, adrenomedullin, and pathogen spectrum). Methods/design: A total of 200 patients with sepsis or septic shock will receive standard-of-care treatment (SoC). Of these, 133 patients (selected by 1:2 randomization) will in addition receive infusions of IgGAM for 5 days. All patients will be followed for approximately 90 days and assessed by the multiple-organ failure (MOF) score, by the EQ QLQ 5D quality-of-life scale, and by measurement of vital signs, biomarkers (as above), and survival. Discussion: This study is intended to provide further information on the efficacy and safety of treatment with IgGAM and to offer the possibility of correlating these with the biomarkers to be studied. Specifically, it will test (at a descriptive level) the hypothesis that patients receiving IgGAM who have higher inflammation status (IL-6) and poorer immune status (low HLA-DR, low immunoglobulin levels) have a better outcome than patients who do not receive IgGAM. It is expected to provide information that will help to close the knowledge gap concerning the association between the effect of IgGAM and the presence of various biomarkers, thus possibly opening the way to a personalized medicine. Trial registration: EudraCT, 2016–001788-34; ClinicalTrials.gov, NCT03334006. Registered on 17 Nov 2017. Trial sponsor: RWTH Aachen University, represented by the Center for Translational & Clinical Research Aachen (contact Dr. S. Isfort)

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

The bacterial actin-like cell division protein FtsA forms antiparallel double filaments upon binding of FtsN

Cell division is essential for the propagation of all living organisms. In the vast majority of bacteria, cell division is carried out by the divisome, a multiprotein machine spanning the cell envelope. The divisome performs membrane invagination, peptidoglycan synthesis and remodelling, and eventually cell separation. Filaments of the tubulin homologue FtsZ form the scaffold for divisome assembly in the cytoplasm, the Z ring. Actin like FtsA tethers FtsZ to the inner membrane and facilitates recruitment of downstream divisome components. The late divisome component FtsN is a bitopic membrane protein that activates peptidoglycan synthesis. Recent genetic studies have suggested that the interaction of FtsA and FtsN is crucial for divisome integrity and function. So far biochemical and structural evidence for the FtsA-FtsN interaction have remained scarce or absent, and we have no mechanistic understanding of its putative signalling function. In this study, I show that Escherichia coli FtsA, upon binding the short, cytoplasmic part of FtsN, forms antiparallel double filaments on lipid monolayers. My complementary X ray crystallography studies provide a near atomic resolution structure of the FtsA double filament and a first insight into the putative FtsA FtsN binding site. FtsA filaments resemble the antiparallel double filaments formed by the actin homologue MreB involved in cell elongation. MreB filaments sense curvature and serve as a rudder in the cell elongation complex, ensuring oriented insertion of peptidoglycan around the cell circumference. Following from that I propose that curvature sensing is conserved in FtsA double filaments and, together with treadmilling FtsZ filaments, provides a guiding mechanism for membrane constriction and septal peptidoglycan synthesis during cell division.Boehringer Ingelheim Fonds PhD fellowship (Honorary) Vice-Chancellor's Award, Cambridge Commonwealth, European & International Trust MRC studentshi

Intravenous IgM-enriched immunoglobulins in critical COVID-19

$\bf Background:$ A profound inflammation-mediated lung injury with long-term acute respiratory distress and high mortality is one of the major complications of critical COVID-19. Immunoglobulin M (IgM)-enriched immunoglobulins seem especially capable of mitigating the inflicted inflammatory harm. However, the efficacy of intravenous IgM-enriched preparations in critically ill patients with COVID-19 is largely unclear. $\bf Methods:$ In this retrospective multicentric cohort study, 316 patients with laboratory-confirmed critical COVID-19 were treated in ten German and Austrian ICUs between May 2020 and April 2021. The primary outcome was 30-day mortality. Analysis was performed by Cox regression models. Covariate adjustment was performed by propensity score weighting using machine learning-based SuperLearner to overcome the selection bias due to missing randomization. In addition, a subgroup analysis focusing on different treatment regimens and patient characteristics was performed. $\bf Results:$ Of the 316 ICU patients, 146 received IgM-enriched immunoglobulins and 170 cases did not, which served as controls. There was no survival difference between the two groups in terms of mortality at 30 days in the overall cohort ($HR_{adj}$: 0.83; 95% CI: 0.55 to 1.25; $\it p$ = 0.374). An improved 30-day survival in patients without mechanical ventilation at the time of the immunoglobulin treatment did not reach statistical significance ($HR_{adj}$: 0.23; 95% CI: 0.05 to 1.08; $\it p$ = 0.063). Also, no statistically significant difference was observed in the subgroup when a daily dose of $\geq$ 15 g and a duration of $\geq$ 3 days of IgM-enriched immunoglobulins were applied ($HR_{adj}$: 0.65; 95% CI: 0.41 to 1.03; $\it p$ = 0.068). $\bf Conclusions:$ Although we cannot prove a statistically reliable effect of intravenous IgM-enriched immunoglobulins, the confidence intervals may suggest a clinically relevant effect in certain subgroups. Here, an early administration (i.e. in critically ill but not yet mechanically ventilated COVID-19 patients) and a dose of $\geq$ 15 g for at least 3 days may confer beneficial effects without concerning safety issues. However, these findings need to be validated in upcoming randomized clinical trials