Die Bedeutung von Toll-like Rezeptoren für die kardiale Inflammation und Funktion während polymikrobieller Sepsis der Maus

Die Sepsis und der mit ihr verbundene septische Schock stellt eine der häufigsten Todesursachen auf Intensivstationen in aller Welt dar. Hierfür mitverantwortlich ist insbesondere die septische Kardiomyopathie. In der jüngeren Vergangenheit konnte gezeigt werden, dass Kardiomyozyten selbst in der Lage sind nach Kontakt mit pathogenen Bakterienbestandteilen eine inflammatorische Antwort zu produzieren, die mit einem Kontraktilitätsverlust einherging. In der vorliegenden Arbeit sollte untersucht werden, inwiefern das angeborene Immunsystem über kardiale Toll-like Rezeptoren während einer polymikrobiellen Sepsis eine kardiale Inflammation vermittelt und zu einer Alteration hämodynamischer Parameter führt. Hierzu wurde im Mausmodell eine polymikrobielle Sepsis via colon ascendens stent peritonitis-OP (CASP-OP) induziert und nach definierten Zeiträumen erfolgte eine Analyse kardialer Inflammationsparameter in WT-Mäusen und Mäusen, die für die TLR 2 und TLR9 defizient waren (TLR2-D, TLR9-D). Es wurden außerdem hämodynamische Analysen mit einem linksventrikulären Druck-Volumen-Katheter durchgeführt. Es zeigte sich, dass sich durch die CASP-OP eine zeitlich dynamische kardiale Inflammation induzieren lässt, die in WT und TLR2-D Tieren ähnlich verläuft. In TLR9-D Mäusen zeigte sich jedoch eine deutlich abgeschwächte kardiale Inflammation. Korrespondierend hierzu war in WT und TLR2-D Tieren eine deutliche Reduktion der kardialen Kontraktilität, des endsystolischen linksventrikulären Druckes und letztlich des Herzzeitvolumens zu beobachten. In TLR9-D Tieren war hingegen die kardiale Performance verglichen mit nicht-septischen Kontrolltieren nicht affektiert. Somit scheint der TLR 9 eine entscheidende Rolle bei der Vermittlung der kardialen Inflammation während polymikrobieller Sepsis im Mausmodell zu spielen

Didaktische Bausteine und Übungen zur Klinischen Sozialarbeit in der Lehre

Die Bausteine und Übungen zur Klinischen Sozialarbeit sind eine Sammlung praktischer Übungen, die im Rahmen von Seminaren mit Studierenden oder in Fort- und Weiterbildungskursen durchgeführt werden können. Themenbereiche: Veranschaulichung abstrakter Modelle / Konzepte und ihre Umsetzung in anwendungsbezogene Erfahrungsmöglichkeiten und Praxisbezüge; Durchführung von Verfahren der Diagnostik, einschließlich Auswertung und Vermittlung von "Erkenntnissen" an Adressaten; Üben von Methoden der Gesprächsführung / Beratung mit Einzelnen, Paaren, Familien und Gruppen; Veranschaulichen und Üben von aktionalen Interventionen; Einsatz von kreativen Medien und multimedialer Arbeit; Anregung und Strukturierung von Selbstreflexionsprozessen (einschl. Reflexion der Beziehungskompetenzen u. Übertragungs-/ Gegenübertragungsprozesse

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Vascular dysfunction following polymicrobial sepsis: role of pattern recognition receptors.

AIMS: Aim was to elucidate the specific role of pattern recognition receptors in vascular dysfunction during polymicrobial sepsis (colon ascendens stent peritonitis, CASP). METHODS AND RESULTS: Vascular contractility of C57BL/6 (wildtype) mice and mice deficient for Toll-like receptor 2/4/9 (TLR2-D, TLR4-D, TLR9-D) or CD14 (CD14-D) was measured 18 h following CASP. mRNA expression of pro- (Tumor Necrosis Factor-α (TNFα), Interleukin (IL)-1β, IL-6) and anti-inflammatory cytokines (IL-10) and of vascular inducible NO-Synthase (iNOS) was determined using RT-qPCR. Wildtype mice exhibited a significant loss of vascular contractility after CASP. This was aggravated in TLR2-D mice, blunted in TLR4-D animals and abolished in TLR9-D and CD14-D animals. TNF-α expression was significantly up-regulated after CASP in wildtype and TLR2-D animals, but not in mice deficient for TLR4, -9 or CD14. iNOS was significantly up-regulated in TLR2-D animals only. TLR2-D animals showed significantly higher levels of TLR4, -9 and CD14. Application of H154-ODN, a TLR9 antagonist, attenuated CASP-induced cytokine release and vascular dysfunction in wildtype mice. CONCLUSIONS: Within our model, CD14 and TLR9 play a decisive role for the development of vascular dysfunction and thus can be effectively antagonized using H154-ODN. TLR2-D animals are more prone to polymicrobial sepsis, presumably due to up-regulation of TLR4, 9 and CD14

Toll-Like Receptor 9 Promotes Cardiac Inflammation and Heart Failure during Polymicrobial Sepsis

Background. Aim was to elucidate the role of toll-like receptor 9 (TLR9) in cardiac inflammation and septic heart failure in a murine model of polymicrobial sepsis. Methods. Sepsis was induced via colon ascendens stent peritonitis (CASP) in C57BL/6 wild-type (WT) and TLR9-deficient (TLR9-D) mice. Bacterial load in the peritoneal cavity and cardiac expression of inflammatory mediators were determined at 6, 12, 18, 24, and 36 h. Eighteen hours after CASP cardiac function was monitored in vivo. Sarcomere length of isolated cardiomyocytes was measured at 0.5 to 10 Hz after incubation with heat-inactivated bacteria. Results. CASP led to continuous release of bacteria into the peritoneal cavity, an increase of cytokines, and differential regulation of receptors of innate immunity in the heart. Eighteen hours after CASP WT mice developed septic heart failure characterised by reduction of end-systolic pressure, stroke volume, cardiac output, and parameters of contractility. This coincided with reduced cardiomyocyte sarcomere shortening. TLR9 deficiency resulted in significant reduction of cardiac inflammation and a sustained heart function. This was consistent with reduced mortality in TLR9-D compared to WT mice. Conclusions. In polymicrobial sepsis TLR9 signalling is pivotal to cardiac inflammation and septic heart failure

Prevention of CASP induced aortic cytokine and iNOS production following TLR9 antagonist treatment.

<p><b>A-E</b> 24 h of exposure to the synthetic TLR9 antagonist H154-thioate did not induce mRNA expression of the investigated cytokines, but prevented the CASP-dependent rise in mRNA expression of inflammatory mediators. There was no observable influence of H154-thioate on iNOS expression. <b>F</b> H154-thioate treatment prior to CASP completely prevented the CASP-induced arterial hypocontractility observed in WT animals (F) (*p<0.05; **p<0.01; ***p<0.001; n≥5 animals in each group; mean ± SEM).</p

Effects of CASP and expression of PRR expression in the murine vessel wall.

<p>PRR mRNA expression during control conditions and following CASP-surgery (TLR2 (A), TLR4 (B), TLR9 (C), CD14 (D)). TLR2-D mice showed significantly higher baseline levels of TLR4 (B), TLR9 (C) and CD14 (D) compared to the other groups. All PRRs appeared to be regulated after CASP; however, only TLR2 and CD14 mRNA expression reached the level of significance (A, D; *p<0.05; **p<0.01; ***p<0.001; n≥5 animals in each group; mean ± SEM).</p

Influence of TLR2 agonism on aortic contractility.

<p>LTA application to WT mice increased contraction force at 10⁻⁷ M phenylephrine. Results were standardized to the maximum contraction force, which was not different between both groups (*p<0.05; n≥5 animals in each group; mean ± SEM).</p

CASP induced aortic cytokine and iNOS production.

<p><b>A</b> Pro-inflammatory TNF-α was significantly up-regulated in WT mice compared to sham animals. CASP-surgery in TLR2-D animals lead to even higher levels of TNF-α compared to all other groups. <b>B, C</b> IL-1β and IL-6 were significantly up-regulated in TLR2-D animals after CASP compared to the other strains. <b>D</b> CASP induced a non-significant up-regulation of the anti-inflammatory cytokine IL-10 in WT, TLR2-D and CD14-D mice. <b>E</b> CASP induced a significant up-regulation of iNOS in TLR2-D mice only. (*p<0.05; **p<0.01; ***p<0.001; n≥5 animals in each group; mean ± SEM).</p