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Background In elderly patients following surgery, postoperative delirium (POD) is the most frequent complication and is associated with negative outcomes. The 2017 European Society of Anaesthesiology guideline on POD aims to improve patient care by implementing structured delirium prevention, diagnosis and treatment. However, these recommendations, especially systematic delirium screening, are still incompletely adopted in clinical practice. The aim of this study was to evaluate the feasibility and acceptance of validated delirium screening tools and to identify barriers to their implementation on nonintensive care unit wards. Methods Screening rates, as well as practicability, acceptance and the interprofessional handling of positive results, were assessed for each group. Screening rates were calculated as a percentage of the total potential testing episodes completed (up to 15 per patient). Patients were considered eligible when aged 65 years and above. Barriers and motivating factors were assessed in a mixed method approach by utilising questionnaires and focus group discussions. Intervention In a 3-month phase, a guideline-compliant screening protocol involving screening for POD three times daily for 5 days following surgery was introduced in five wards: both the 4-item assessment test (4AT) and the nursing delirium screening scale (NuDESC) were used. Before commencing the study and again after 6 weeks, medical staff of the respective wards underwent a 45 min training session. Results Of a total of 3183 potential testing episodes, 999 (31.4%) were completed, with more NuDESC observational tests (43%) than 4AT bedside tests completed (20%). The 4AT was considered more difficult to integrate into daily working routines, it took longer to administer, and nurses felt uncomfortable conducting the screening (53 vs. 13%). Screening results indicating delirium were often not discussed within the team (47%), and nurses felt that often such results were not taken seriously by physicians (54%). Conclusion The observational NuDESC showed a higher completion rate than the bedside 4AT, although overall testing rates were low. The necessary time needed to conduct the screening, the negative reactions by patients, insufficient team communication and a lack of initiation of any therapy were identified as major barriers in the implementation of the guideline-compliant screening protocol. For all staff, further education and awareness of the importance of POD diagnosis and treatment might improve the screening rates. The NuDesc received better results concerning acceptance, practicability and introduction into daily work routine, leading to higher screening rates compared with the 4AT. The latter instrument, which was intended to be used rather selectively or when POD is suspected, might therefore not be suitable for guideline-compliant regular and repeated screening for POD.

Despite its fundamental role in providing an extensive surface for gas exchange, the alveolar epithelium (AE) serves as an immunological barrier through, e.g., the release of proinflammatory cytokines and secretion of surfactant to prevent alveolar collapse. Thus, AE is important for sustaining lung homeostasis. Extracellular ATP secreted by alveolar epithelial cells (AECs) is involved in physiological and pathological conditions and acts mainly through the activation of purine receptors (P2Rs). When studying P2R-mediated processes, primary isolated type II AECs (piAECs) still represent the gold standard in in vitro research, although their preparation is time-consuming and requires the sacrifice of many animals. Hence, cultivated immortalized and tumor-derived AEC lines may constitute a valuable alternative. In this work, we examined P2R expression and functionality in piAECs, in immortalized and tumor-derived AEC lines with the purpose of gaining a better understanding of purinergic signaling in different cell systems and assisting researchers in the choice of a suitable cell line with a certain P2R in demand. We combined mRNA and protein analysis to evaluate the expression of P2R. For pharmacological testing, we conducted calcium ([Ca(2+)]) measurements and siRNA receptor knockdown. Interestingly, the mRNA and protein levels of P2Y(2), P2Y(6,) and P2X(4) were detected on all cell lines. Concerning functionality, P2XR could be narrowed to L2 and piAECs while P2YR were active in all cell lines. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11302-020-09696-0) contains supplementary material, which is available to authorized users.

Extravasation of circulating tumor cells (CTCs) is critical for metastasis and is initiated by adhesive interactions between glycoligands on CTCs and E-selectin on endothelia. Here, we show that the clinically approved proteasome inhibitor bortezomib (BZM; Velcade) counteracts the cytokine-dependent induction of E-selectin in the lung mediated by the primary tumor, thereby impairing endothelial adhesion and thus spontaneous lung metastasis in vivo. However, the efficacy of BZM crucially depends on the tumor cells' E-selectin ligands, which determine distinct adhesion patterns. The canonical ligands sialyl-Lewis A (sLeA) and sLeX mediate particularly high-affinity E-selectin binding so that the incomplete E-selectin-reducing effect of BZM is not sufficient to disrupt adhesion or metastasis. In contrast, tumor cells lacking sLeA/X nevertheless bind E-selectin, but with low affinity, so that adhesion and lung metastasis are significantly diminished. Such low-affinity E-selectin ligands apparently consist of sialylated MGAT5 products on CD44. BZM no longer has anti-metastatic activity after CD44 knockdown in sLeA/X-negative tumor cells or E-selectin knockout in mice. sLeA/X can be determined by immunohistochemistry in cancer samples, which might aid patient stratification. These data suggest that BZM might act as a drug for inhibiting extravasation and thus distant metastasis formation in malignancies expressing low-affinity E-selectin ligands.

Dysfunction of the pulmonary endothelium is associated with most lung diseases. Extracellular nucleotides modulate a plethora of endothelial functions in the lung such as vessel integrity, vasodilatation, inflammatory, and thrombotic responses as well as survival and DNA repair, mostly via Ca2+ signaling pathways. However, a comprehensive analysis of the molecular components of the underlying P2 receptor-mediated Ca2+ signaling pathways in the lung has not been conducted so far. Therefore, our aim was to identify the principal P2 receptor Ca2+ signalosome in the human pulmonary endothelium and investigate potential dysregulation in pulmonary vascular disease. Comparative transcriptomics and quantitative immunohistochemistry were performed on publicly available RNA sequencing and protein datasets to identify the specific expression profile of the P2-receptor Ca2+ signalosome in the healthy human pulmonary endothelium and endothelial cells (EC) dysfunctional due to loss of or defective bone morphogenetic protein receptor (BMPR2). Functional expression of signalosome components was tested by single cell Ca2+ imaging. Comparative transcriptome analysis of 11 endothelial cell subtypes revealed a specific P2 receptor Ca2+ signalosome signature for the pulmonary endothelium. Pulmonary endothelial expression of the most abundantly expressed Ca2+ toolkit genes CALM1, CALM2, VDAC1, and GNAS was confirmed by immunohistochemistry (IHC). P2RX1, P2RX4, P2RY6, and P2YR11 showed strong lung endothelial staining by IHC, P2X5, and P2Y1 were found to a much lesser extent. Very weak or no signals were detected for all other P2 receptors. Stimulation of human pulmonary artery (HPA) EC by purine nucleotides ATP, ADP, and AMP led to robust intracellular Ca2+ signals mediated through both P2X and P2Y receptors. Pyrimidine UTP and UDP-mediated Ca2+ signals were generated almost exclusively by activation of P2Y receptors. HPAEC made dysfunctional by siRNA-mediated BMPR2 depletion showed downregulation of 18 and upregulation of 19 P2 receptor Ca2+ signalosome genes including PLCD4, which was found to be upregulated in iPSC-EC from BMPR2-mutant patients with pulmonary arterial hypertension. In conclusion, the human pulmonary endothelium expresses a distinct functional subset of the P2 receptor Ca2+ signalosome. Composition of the P2 receptor Ca2+ toolkit in the pulmonary endothelium is susceptible to genetic disturbances likely contributing to an unfavorable pulmonary disease phenotype found in pulmonary arterial hypertension.

Bacterial pneumonia is a global health challenge that causes up to 2 million deaths each year. Purinergic signaling plays a pivotal role in healthy alveolar epithelium. Here, we used fluorophore-based analysis and live-cell calcium imaging to address the question of whether the bacterial pathogen Streptococcus pneumoniae directly interferes with purinergic signaling in alveolar epithelial cells. Disturbed purinergic signaling might result in pathophysiologic changes like edema formation and atelectasis, which are commonly seen in bacterial pneumonia. Purine receptors are mainly activated by ATP, mediating a cytosolic calcium response. We found that this purinergic receptor P2Y(2)-mediated response is suppressed in the presence of S. pneumoniae in A549 and isolated primary alveolar cells in a temperature-dependent manner. Downstream inositol 3-phosphate (IP(3)) signaling appeared to be unaffected, as calcium signaling via protease-activated receptor 2 remained unaltered. S. pneumoniae–induced suppression of the P2Y(2)-mediated calcium response depended on the P2Y(2) phosphorylation sites Ser-243, Thr-344, and Ser-356, which are involved in receptor desensitization and internalization. Spinning-disk live-cell imaging revealed that S. pneumoniae induces P2Y(2) translocation into the cytosol. In conclusion, our results show that S. pneumoniae directly inhibits purinergic signaling by inducing P2Y(2) phosphorylation and internalization, resulting in the suppression of the calcium response of alveolar epithelial cells to ATP, thereby affecting cellular integrity and function.

Introduction Postoperative nausea and vomiting (PONV) is common in patients after craniotomy and may lead to severe postoperative complications. The aim of this study was to identify risk factors and postoperative complications associated with PONV in the context of perioperative high-dose dexamethasone administration. Patients and Methods In this prospective single-center study, all patients planned for elective craniotomy for supra- and infratentorial lesions were eligible to be included. Any PONV in a 24-hour period after craniotomy was recorded and analyzed with regard to time to postoperative complications and the administration of perioperatively administered high-dose dexamethasone. Results The overall PONV rate of 421 patients during a 9-month period was 18.1% (76 patients). Multivariate analysis revealed a significant association of PONV with female sex, infratentorial localization, age, and history of PONV. There was no association between PONV and postoperative complications such as intracranial hemorrhage, cerebrospinal fluid (CSF) leaks, or pneumonia. Perioperative administration of high-dose dexamethasone for prophylactic prevention of edema was the only significant risk factor for postoperative complications (odds ratio [OR]: 3.34; confidence interval [CI], 1.39–8.05; p Conclusion The low PONV rate of 18.1% in this study may be the result of the frequent perioperative administration of high-dose dexamethasone for the prevention of edema. Our data indicate that perioperative high-dose dexamethasone is significantly associated with CSF leaks and can therefore not be recommended on a regular basis.

IntroductionWith increasing age, the risk of complications after surgery rises in elderly patients. Furthermore, the prevalence of multimorbidity and polypharmacy rises with age, making this elderly population especially vulnerable for drug-related problems and posing an additional risk for postoperative complications. Still, only few studies have concentrated on investigating how medication safety can be improved in these patients. The aim of this pilot study is to examine the impact of a comprehensive intervention (interprofessional systematic medication therapy management) on medication appropriateness in elderly polymedicated, multimorbid patients during hospital stay for elective surgery.Methods and analysisThis pilot study will include a total number of 140 patients. Surgical high-risk patients ≥65 years taking more than five chronic systemic drugs will be recruited consecutively for 9 months in the control group capturing usual care regarding medication history and in-hospital medication therapy management without any study intervention. Recruitment of the intervention group will be conducted for another 9 months. The intervention consists of the following components: an additional medication history by a hospital pharmacist before admission, a subsequent medication review, optimisation of the long-term medication and recommendations to the patient’s general practitioner. A follow-up will be performed 3 months after surgery. As the primary study outcome, medication appropriateness will be measured using the Medication Appropriateness Index.Secondary outcomes are postoperative complications, incidence and frequency of adverse drug reactions and potentially inappropriate medication in the elderly, satisfaction with inpatient and outpatient care, medication reconciliation and health-related quality of life. Multivariable analyses will be used to analyse all quantitative research questions.Ethics and disseminationEthics approval was obtained by the medical ethics committee of the Medical Chamber of Hamburg (study ID: PV5754). Data will be published in peer-reviewed journals and presented at conferences.Trial registration numberThe study is registered at www.drks.de: DRKS00014621.

ZusammenfassungFrailty (Gebrechlichkeit) ist eine Einschränkung der physiologischen Reserve bei älteren Patienten mit schwerwiegenden individuellen und sozioökonomischen Folgen. Multiple Aspekte der Patientenbehandlung sowie das Outcome werden durch Frailty nachhaltig beeinflusst. Obwohl mehr als 60 Messinstrumente existieren, sind die Erfassung und Berücksichtigung funktioneller Assessments in der klinischen Routine unzureichend umgesetzt. Das interdisziplinäre und interprofessionelle Verständnis, warum und wie Frailty beurteilt werden sollte, ist die Grundlage für die dauerhafte Implementierung. Der Artikel zeigt die Auswirkungen von Frailty und Vorteile einer Früherkennung auf und gibt einen Überblick über die wichtigsten Instrumente, die in der Frailty-Erkennung und -Bewertung verwendet werden können. Die frühe präoperative Detektion bietet ein vielfältiges Optimierungspotenzial für die peri- und intraoperative Versorgung. Verschiedene Frailty-Assessment-Tools körperlicher, kognitiver und psychosozialer Domänen werden vorgestellt und diskutiert. Frailty-Assessments variieren immens in Bezug auf die erforderliche Zeit, die Ausrüstung und das Fachwissen zur Durchführung. Wir empfehlen mindestens einen Test für die einzelnen Dimensionen von Frailty, um ein holistisches Bild der geriatrischen Patienten zu erhalten. Die Bewertung von Frailty sollte übergreifend in die interdisziplinären Strukturen der klinischen Routine implementiert werden, um die Patientensicherheit sowie das kurz- und langfristige Outcome zu verbessern.

ZusammenfassungAufgrund der steigenden Lebenserwartung müssen sich heutzutage immer mehr ältere und hochbetagte Patienten einer Operation unterziehen – eine Herausforderung für die Chirurgie und insbesondere für die Anästhesiologie. Dieser Beitrag beschreibt, wie altersbedingte Besonderheiten präoperativ erfasst und entsprechende Maßnahmen eingeleitet werden können, um das Risiko der postoperativen Morbidität – oder gar Pflegebedürftigkeit – zu verringern.

Background The efficacy of selective Janus kinase 1/3 inhibitor R507 to prevent obliterative airway disease was analyzed in preclinical airway transplantation models. Methods Orthotopic trachea transplantations were performed between Lewis donors and Brown Norway rat recipients. Oral everolimus (4 mg/kg once per day) or oral respective inhaled R507 (60 mg/kg twice per day, each) was used for immunosuppression. Grafts were retrieved after 6 or 60 days. Toxicity and anti-inflammatory effects of R507 were analyzed on human airway epithelial cells. Results In 6-day animals, oral and inhaled R507 more potently diminished mononuclear graft infiltration than everolimus and preserved ciliated pseudostratified columnar respiratory epithelium. Everolimus and R507 similarly suppressed systemic cellular and humoral immune activation. In untreated rats, marked obliterative airway disease developed over 60 days. Oral and inhaled R507 was significantly more effective in reducing airway obliteration and preserved the morphology of the airway epithelium. Luciferase-positive donors revealed that a substantial amount of smooth muscle cells within the obliterative tissue was of donor origin. Only everolimus but not R507, adversely altered kidney function and lipid profiles. The R507 aerosol did not show airway toxicity in vitro but effectively suppressed activation of inflammatory signaling pathways induced by IL-1β. Conclusions The Janus kinase 1/3 inhibitor R507 is a very well-tolerated immunosuppressant that similarly diminished obliterative airway disease with systemic or inhaled administration.

Background Older patients are undergoing surgery in increasing numbers. Frailty is a key risk factor associated with higher rates of complications and mortality, longer hospital stays, and functional impairment. Methods This review is based on pertinent publications retrieved by a selective search in PubMed, including guidelines from Germany and abroad. Results Many studies have been published on the assessment of frailty and its consequences, but the scientific investigation of this topic and the clinical utility of the findings are made more difficult by the lack of a uniform definition and of uniform instruments for assessment. Some definitions of frailty include only physical aspects, while others encompass cognitive, emotional, and social factors as well. Despite this variability, the assessment of frailty enables better estimation of the perioperative risk so that the patient can be optimally prepared for the operation. Especially for frail elderly patients, an interdisciplinary approach is called for over the entire perioperative treatment period. Conclusion In the future, the definition of frailty will need to be standardized so that this parameter can be properly assessed and investigated in comparative studies.

Background Elderly patients are a growing and vulnerable group with an elevated perioperative risk. Perioperative treatment pathways that take these patients' special risks and requirements into account are often not implemented in routine clinical practice. Methods This review is based on pertinent publications retrieved by a selective search in PubMed, the AWMF guideline database, and the Cochrane database for guidelines from Germany and abroad, meta-analyses, and Cochrane reviews. Results The care of elderly patients who need surgery calls for an interdisciplinary, interprofessional treatment concept. One component of this concept is preoperative preparation of the patient ("prehabilitation"), which is best initiated before hospital admission, e.g., correction of deficiency states, optimization of chronic drug treatment, and respiratory training. Another important component consists of pre-, intra-, and postoperative measures to prevent delirium, which can lower the frequency of this complication by 30-50%: these include orientation aids, avoidance of inappropriate drugs for elderly patients, adequate analgesia, early mobilization, short fasting times, and a perioperative nutrition plan. Preexisting cognitive impairment predisposes to postoperative delirium (odds ratios [OR] ranging from 2.5 to 4.5). Frailty is the most important predictor of the postoperative course (OR: 2.6-11). It follows that preoperative assessment of the patient's functional and cognitive status is essential. Concluzion The evidence-based and guideline-consistent care of elderly patients requires not only close interdisciplinary, interprofessional, and cross-sectoral collaboration, but also the restructuring and optimization of habitual procedural pathways in the hospital. Elderly patients' special needs can only be met by a treatment concept in which the entire perioperative phase is considered as a single, coherent process.

Dysfunction of the pulmonary endothelium is associated with most lung diseases. Extracellular nucleotides modulate a plethora of endothelial functions in the lung such as vessel integrity, vasodilatation, inflammatory, and thrombotic responses as well as survival and DNA repair, mostly via Ca(2+) signaling pathways. However, a comprehensive analysis of the molecular components of the underlying P2 receptor-mediated Ca(2+) signaling pathways in the lung has not been conducted so far. Therefore, our aim was to identify the principal P2 receptor Ca(2+) signalosome in the human pulmonary endothelium and investigate potential dysregulation in pulmonary vascular disease. Comparative transcriptomics and quantitative immunohistochemistry were performed on publicly available RNA sequencing and protein datasets to identify the specific expression profile of the P2-receptor Ca(2+) signalosome in the healthy human pulmonary endothelium and endothelial cells (EC) dysfunctional due to loss of or defective bone morphogenetic protein receptor (BMPR2). Functional expression of signalosome components was tested by single cell Ca(2+) imaging. Comparative transcriptome analysis of 11 endothelial cell subtypes revealed a specific P2 receptor Ca(2+) signalosome signature for the pulmonary endothelium. Pulmonary endothelial expression of the most abundantly expressed Ca(2+) toolkit genes CALM1, CALM2, VDAC1, and GNAS was confirmed by immunohistochemistry (IHC). P2RX1, P2RX4, P2RY6, and P2YR11 showed strong lung endothelial staining by IHC, P2X5, and P2Y1 were found to a much lesser extent. Very weak or no signals were detected for all other P2 receptors. Stimulation of human pulmonary artery (HPA) EC by purine nucleotides ATP, ADP, and AMP led to robust intracellular Ca(2+) signals mediated through both P2X and P2Y receptors. Pyrimidine UTP and UDP-mediated Ca(2+) signals were generated almost exclusively by activation of P2Y receptors. HPAEC made dysfunctional by siRNA-mediated BMPR2 depletion showed downregulation of 18 and upregulation of 19 P2 receptor Ca(2+) signalosome genes including PLCD4, which was found to be upregulated in iPSC-EC from BMPR2-mutant patients with pulmonary arterial hypertension. In conclusion, the human pulmonary endothelium expresses a distinct functional subset of the P2 receptor Ca(2+) signalosome. Composition of the P2 receptor Ca(2+) toolkit in the pulmonary endothelium is susceptible to genetic disturbances likely contributing to an unfavorable pulmonary disease phenotype found in pulmonary arterial hypertension. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11302-019-09674-1) contains supplementary material, which is available to authorized users.

BackgroundIn acute respiratory distress syndrome (ARDS), pulmonary perfusion failure increases physiologic dead space ventilation (VD/VT), leading to a decline of the alveolar CO2 concentration [CO2]iA. Although it has been shown that alveolar hypocapnia contributes to formation of atelectasis and surfactant depletion, a typical complication in ARDS, the underlying mechanism has not been elucidated so far.MethodsIn isolated perfused rat lungs, cytosolic or mitochondrial Ca2+ concentrations ([Ca2+]cyt or [Ca2+]mito, respectively) of alveolar epithelial cells (AECs), surfactant secretion and the projected area of alveoli were quantified by real-time fluorescence or bright-field imaging (n=3–7 per group). In ventilated White New Zealand rabbits, the left pulmonary artery was ligated and the size of subpleural alveoli was measured by intravital microscopy (n=4 per group). Surfactant secretion was determined in the bronchoalveolar lavage (BAL) by western blot.ResultsLow [CO2]iA decreased [Ca2+]cyt and increased [Ca2+]mito in AECs, leading to reduction of Ca2+-dependent surfactant secretion, and alveolar ventilation in situ. Mitochondrial inhibition by ruthenium red or rotenone blocked these responses indicating that mitochondria are key players in CO2 sensing. Furthermore, ligature of the pulmonary artery of rabbits decreased alveolar ventilation, surfactant secretion and lung compliance in vivo. Addition of 5% CO2 to the inspiratory gas inhibited these responses.ConclusionsAccordingly, we provide evidence that alveolar hypocapnia leads to a Ca2+ shift from the cytosol into mitochondria. The subsequent decline of [Ca2+]cyt reduces surfactant secretion and thus regional ventilation in lung regions with high VD/VT. Additionally, the regional hypoventilation provoked by perfusion failure can be inhibited by inspiratory CO2 application.

Frailty (Gebrechlichkeit) ist eine Einschränkung der physiologischen Reserve bei älteren Patienten mit schwerwiegenden individuellen und sozioökonomischen Folgen. Multiple Aspekte der Patientenbehandlung sowie das Outcome werden durch Frailty nachhaltig beeinflusst. Obwohl mehr als 60 Messinstrumente existieren, sind die Erfassung und Berücksichtigung funktioneller Assessments in der klinischen Routine unzureichend umgesetzt. Das interdisziplinäre und interprofessionelle Verständnis, warum und wie Frailty beurteilt werden sollte, ist die Grundlage für die dauerhafte Implementierung. Der Artikel zeigt die Auswirkungen von Frailty und Vorteile einer Früherkennung auf und gibt einen Überblick über die wichtigsten Instrumente, die in der Frailty-Erkennung und -Bewertung verwendet werden können. Die frühe präoperative Detektion bietet ein vielfältiges Optimierungspotenzial für die peri- und intraoperative Versorgung. Verschiedene Frailty-Assessment-Tools körperlicher, kognitiver und psychosozialer Domänen werden vorgestellt und diskutiert. Frailty-Assessments variieren immens in Bezug auf die erforderliche Zeit, die Ausrüstung und das Fachwissen zur Durchführung. Wir empfehlen mindestens einen Test für die einzelnen Dimensionen von Frailty, um ein holistisches Bild der geriatrischen Patienten zu erhalten. Die Bewertung von Frailty sollte übergreifend in die interdisziplinären Strukturen der klinischen Routine implementiert werden, um die Patientensicherheit sowie das kurz- und langfristige Outcome zu verbessern.

The utility of autologous induced pluripotent stem cell (iPSC) therapies for tissue regeneration depends on reliable production of immunologically silent functional iPSC derivatives. However, rejection of autologous iPSC-derived cells has been reported, although the mechanism underlying rejection is largely unknown. We hypothesized that de novo mutations in mitochondrial DNA (mtDNA), which has far less reliable repair mechanisms than chromosomal DNA, might produce neoantigens capable of eliciting immune recognition and rejection. Here we present evidence in mice and humans that nonsynonymous mtDNA mutations can arise and become enriched during reprogramming to the iPSC stage, long-term culture and differentiation into target cells. These mtDNA mutations encode neoantigens that provoke an immune response that is highly specific and dependent on the host major histocompatibility complex genotype. Our results reveal that autologous iPSCs and their derivatives are not inherently immunologically inert for autologous transplantation and suggest that iPSC-derived products should be screened for mtDNA mutations.

With a constantly growing portion of elderly within our population and the advances of modern medicine, surgery on aged and very aged patients has become a daily hospital routine. Due to the physical and mental features of ageing these patients face special perioperative risks. They display a higher rate of complications, morbidity and cognitive deficits which might in the end lead to persisting need of care. Even in the healthy elderly, most organ functions are "physiologically" instable or deficient and the homeostasis of health and disease is fragile. The preoperative evaluation of the aged patient has to be extended towards risk factors and pathologic pre-conditions which derive especially from high age and are so far not determined by a mere "fit-for-anaesthesia?"This includes assessment of frailty and functional status as well as the evaluation of pre-existing cognitive deficits, malnutrition and polypharmacy. Prevention of postoperative cognitive deficits and delirium is an important goal of medical therapy and requires i. a. omission of benzodiazepines, BIS-controlled anaesthesia, focus on patient's comfort and orientation and inclusion of close relatives and confidants in all processes. Considering all this, an elderly patient might require more time than usually given to be well prepared for anaesthesia, surgery and the postoperative course. The altered physiology and the special risk profile of the aged patient demand special attention and time throughout the perioperative phase. With an increasing number of elderly presenting for surgery, it is likely that more age-adapted structures and processes become implemented in our hospitals.Aufgrund der steigenden Lebenserwartung müssen sich heutzutage immer mehr ältere und hochbetagte Patienten einer Operation unterziehen – eine Herausforderung für die Chirurgie und insbesondere für die Anästhesiologie. Dieser Beitrag beschreibt, wie altersbedingte Besonderheiten präoperativ erfasst und entsprechende Maßnahmen eingeleitet werden können, um das Risiko der postoperativen Morbidität – oder gar Pflegebedürftigkeit – zu verringern.

Background: Postoperative nausea and vomiting (PONV) is common after general anesthesia and are reported by approximately 20% to 25% of all patients and up to 39% of patients undergoing neurosurgical procedures. The most common standard prophylaxis is a single application of 4 mg of dexamethasone before initiating anesthesia. Dexamethasone is known to suppress adreno-corticotroph hormone and cortisol levels. The objective was to find out whether this prophylaxis has an effect on the postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery, and therefore simulates pituitary deficiency. Patients and Methods: A retrospective analysis of the files of 136 consecutive patients who were operated during a course of 6 months were included. Nineteen patients with a known history of PONV received a standard dose of 4 mg of dexamethasone perioperatively. Blood tests were drawn at the first postoperative day and were compared with blood tests of patients who had no history of PONV and therefore received no prophylaxis. Results: Patients who were treated with a dexamethasone PONV prophylaxis showed no significant changes in cortisol levels; preoperative median of 93 μg/L (range, 39 to 427) and a postoperative median of 87 μg/L (range, 10 to 733; P=0.798) opposed to patients who did not receive such treatment; preoperative cortisol 114 μg/L (range, 10 to 387) and postoperative levels of 273 μg/L (range, 10 to 1352; P Conclusions: As early postoperative blood checks of the cortisol levels yield important information about potential pituitary sufficiency after transsphenoidal surgery, the probability that dexamethasone PONV prophylaxis suppresses postoperative cortisol levels should be considered.

In adult respiratory distress syndrome (ARDS) pulmonary perfusion failure increases physiologic dead-space (VD/VT) correlating with mortality. High VD/VT results in alveolar hypocapnia, which has been demonstrated to cause edema formation, atelectasis, and surfactant depletion, evoked, at least in part, by apoptosis of alveolar epithelial cells (AEC). However, the mechanism underlying the hypocapnia-induced AEC apoptosis is unknown. Here, using fluorescent live-cell imaging of cultured AEC type 2 we could show that in terms of CO2 sensing the tricarboxylic acid cycle enzyme isocitrate dehydrogenase (IDH) 3 seems to be an important player because hypocapnia resulted independently from pH in an elevation of IDH3 activity and subsequently in an increase of NADH, the substrate of the respiratory chain. As a consequence, the mitochondrial transmembrane potential (ΔΨ) rose causing a Ca2+ shift from cytosol into mitochondria, whereas the IDH3 knockdown inhibited these responses. Furthermore, the hypocapnia-induced mitochondrial Ca2+ uptake resulted in reactive oxygen species (ROS) production, and both the mitochondrial Ca2+ uptake and ROS production induced apoptosis. Accordingly, we provide evidence that in AEC type 2 hypocapnia induces elevation of IDH3 activity leading to apoptosis. This finding might give new insight into the pathogenesis of ARDS and may help to develop novel strategies to reduce tissue injury in ARDS.

In adult respiratory distress syndrome (ARDS) pulmonary perfusion failure increases physiologic dead-space (VD/VT) correlating with mortality. High VD/VT results in alveolar hypocapnia, which has been demonstrated to cause edema formation, atelectasis, and surfactant depletion, evoked, at least in part, by apoptosis of alveolar epithelial cells (AEC). However, the mechanism underlying the hypocapnia-induced AEC apoptosis is unknown. Here, using fluorescent live-cell imaging of cultured AEC type 2 we could show that in terms of CO2 sensing the tricarboxylic acid cycle enzyme isocitrate dehydrogenase (IDH) 3 seems to be an important player because hypocapnia resulted independently from pH in an elevation of IDH3 activity and subsequently in an increase of NADH, the substrate of the respiratory chain. As a consequence, the mitochondrial transmembrane potential (ΔΨ) rose causing a Ca2+ shift from cytosol into mitochondria, whereas the IDH3 knockdown inhibited these responses. Furthermore, the hypocapnia-induced mitochondrial Ca2+ uptake resulted in reactive oxygen species (ROS) production, and both the mitochondrial Ca2+ uptake and ROS production induced apoptosis. Accordingly, we provide evidence that in AEC type 2 hypocapnia induces elevation of IDH3 activity leading to apoptosis. This finding might give new insight into the pathogenesis of ARDS and may help to develop novel strategies to reduce tissue injury in ARDS.

Cystic fibrosis (CF) is an inherited disease associated with chronic severe lung inflammation, leading to premature death. To develop innovative anti-inflammatory treatments, we need to characterize new cellular and molecular components contributing to the mechanisms of lung inflammation. Here, we focused on the potential role of “transient receptor potential vanilloid-4” (TRPV4), a nonselective calcium channel. We used both in vitro and in vivo approaches to demonstrate that TRPV4 expressed in airway epithelial cells triggers the secretion of major proinflammatory mediators such as chemokines and biologically active lipids, as well as a neutrophil recruitment in lung tissues. We characterized the contribution of cytosolic phospholipase A2, MAPKs, and NF-κB in TRPV4-dependent signaling. We also showed that 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids, i.e., four natural lipid-based TRPV4 agonists, are present in expectorations of CF patients. Also, TRPV4-induced calcium mobilization and inflammatory responses were enhanced in cystic fibrosis transmembrane conductance regulator-deficient cellular and animal models, suggesting that TRPV4 is a promising target for the development of new anti-inflammatory treatments for diseases such as CF.

Die Einlungenventilation (ELV) fuhrt sowohl zu Beeintrachtigungen des Gasaustausches als auch zu komplexen Veranderungen der Herz-Kreislauf-Situation. Insbesondere bei kardiopulmonal vorerkrankten Patienten konnen diese Veranderungen klinische Relevanz durch Oxygenierungsstorungen und hamodynamische Instabilitat erlangen. Die Konsequenzen auf den alveolaren Gasaustausch unter ELV wurden in zahlreichen experimentellen und klinischen Studien untersucht. In weiten Bereichen unerforscht sind bislang jedoch die hamodynamischen Konsequenzen der ELV. Auch existieren keine Empfehlungen, welches Verfahren des erweiterten hamodynamischen Monitorings (EHM) zum Erfassen dieser hamodynamischen Veranderungen unter ELV zu bevorzugen ist. Viele Fragen in Bezug auf Einsatzmoglichkeiten und Wertigkeit dieses EHM bei ELV bleiben offen. Dieser Beitrag soll die aktuelle Literatur zu diesem Thema kritisch beleuchten und dazu beitragen, Strategien zu entwickeln, welche Form des EHM bei der ELV klinisch sinnvoll einzusetzen ist.

Hypoxia, which commonly associates with respiratory and cardiovascular diseases, provokes an acute inflammatory response. However, underlying mechanisms are not well understood. Here we report that red blood cells (RBCs) induce hypoxic inflammation by producing reactive oxygen species (ROS) that diffuse to endothelial cells of adjoining blood vessels. Real-time fluorescence imaging of rat and mouse lungs revealed that in the presence of RBC-containing vascular perfusion, hypoxia increased microvascular ROS, and cytosolic Ca2+, leading to P-selectin–dependent leukocyte recruitment. However, in the presence of RBC-free perfusion, all hypoxia-induced responses were completely inhibited. Because hemoglobin (Hb) autoxidation causes RBC superoxide formation that readily dismutates to H2O2, hypoxia-induced responses were lost when we inhibited Hb autoxidation with CO or nitrite, or when the H2O2 inhibitor, catalase was added to the infusion to neutralize the RBC-derived ROS. By contrast, perfusion with RBCs from BERK-trait mice that are more susceptible to Hb autoxidation and to hypoxia-induced superoxide production enhanced the hypoxia-induced responses. We conclude that in hypoxia, increased Hb autoxidation augments superoxide production in RBCs. Consequently, RBCs release H2O2 that diffuses to the lung microvascular endothelium, thereby initiating Ca2+-dependent leukocyte recruitment. These findings are the first evidence that RBCs contribute to hypoxia-induced inflammation.

Background: There is growing evidence that platelets accumulate in the lung and contribute to the pathogenesis of acute lung injury during endotoxemia. The aims of the present study were to localize platelet sequestration in the pulmonary microcirculation and to investigate the role of P-selectin as a molecular mechanism of platelet endothelial cell interaction. Methods: We used in vivo fluorescence microscopy to quantify the kinetics of fluorescently labeled erythrocytes and platelets in alveolar capillary networks in rabbit lungs. Results: Six hours after onset of endotoxin infusion we observed a massive rolling along and firm adherence of platelets to lung capillary endothelial cells whereas under control conditions no platelet sequestration was detected. P-selectin was expressed on the surface of separated platelets which were incubated with endotoxin and in lung tissue. Pretreatment of platelets with fucoidin, a P-selectin antagonist, significantly attenuated the endotoxin-induced platelet rolling and adherence. In contrast, intravenous infusion of fucoidin in endotoxin-treated rabbits did not inhibit platelet sequestration in pulmonary capillaries. Conclusion: We conclude that platelets accumulate in alveolar capillaries following endotoxemia. P-selectin expressed on the surface of platelets seems to play an important role in mediating this platelet-endothelial cell interaction.

SummaryAccumulation of platelets might contribute to acute lung injury during systemic inflammation. The aim of the study was to elucidate the role of the poly (ADP-ribose) synthetase, a nucleotide-polymerizising enzyme, in mediation of platelet-endothelial cell interaction through regulation of adhesion molecules within the pulmonary microcirculation during endotoxemia. We used in vivo fluorescence microscopy to quantify kinetics of fluorescently labeled erythrocytes and platelets in rabbit pulmonary arterioles and venules. Six hours after onset of endotoxin infusion we observed a massive interaction of platelets with the microvascular endothelial cells, whereas under control conditions, no platelet sequestration was measured. An up-regulation of P- and E-selectin was detected in lung tissue following endotoxin infusion by immunohistochemistry and Western blot analysis. Blockade of endothelial P-selectin with fucoidin resulted in a reduction of the endotoxin-induced platelet-endothelial cell interaction. Inhibition of poly (ADP-ribose) synthetase by 3-aminobenzamide inhibited the endotoxin-induced expression of endothelial P- and E-selectin and the subsequent recruitment of platelets. In summary, we provide first in vivo evidence that platelets accumulate in pulmonary microcirculation following endotoxemia. Poly (ADP-ribose) synthetase seems to mediate this platelet-endothelial cell interaction via P- and E-selectin expressed on the surface of microvascular endothelium.

PMCID: PMC4323184.-- et al., Despite the introduction of antiproliferative drug-eluting stents, coronary heart disease remains the leading cause of death in the United States. In-stent restenosis and bypass graft failure are characterized by excessive smooth muscle cell (SMC) proliferation and concomitant myointima formation with luminal obliteration. Here we show that during the development of myointimal hyperplasia in human arteries, SMCs show hyperpolarization of their mitochondrial membrane potential (Δ Ψ m) and acquire a temporary state with a high proliferative rate and resistance to apoptosis. Pyruvate dehydrogenase kinase isoform 2 (PDK2) was identified as a key regulatory protein, and its activation proved necessary for relevant myointima formation. Pharmacologic PDK2 blockade with dichloroacetate or lentiviral PDK2 knockdown prevented Δ Ψ m hyperpolarization, facilitated apoptosis and reduced myointima formation in injured human mammary and coronary arteries, rat aortas, rabbit iliac arteries and swine (pig) coronary arteries. In contrast to several commonly used antiproliferative drugs, dichloroacetate did not prevent vessel re-endothelialization. Targeting myointimal Δ Ψ m and alleviating apoptosis resistance is a novel strategy for the prevention of proliferative vascular diseases. © 2014 Macmillan Publishers Limited., This study was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft (DFG), SCHR992/3-1 and SCHR992/4-1 to S.S.), the International Society for Heart and Lung Transplantation (ISHLT, to S.S.), the Förderverein des Universitären Herzzentrums Hamburg (to S.S.), the Hermann and Lilly Schilling Foundation (to C.K.), the MINECO (SAF2013-41177-R, to J.P.B.) and the NIH (NIH 1R01HL105299, to P.S.T.).

e23010Background: E-selectin-mediated adhesion of circulating tumor cells (CTCs) to vascular endothelial cells (ECs) initiates CTC extravasation at a distant site and is hence a critical step of th...

The endothelial glycocalyx (GLX) is pivotal to vascular barrier function. We investigated the consequences of GLX degradation on pulmonary microvascular perfusion and, prompted by evidence that hydroxyethyl starch (HES) improves microcirculation, studied the effects of two HES preparations during GLX diminution. C57 BL/6 black mice lungs were explanted and perfused with 1-mL/min buffer solution containing autologous erythrocytes (red blood cells) at a hematocrit of 5%. Microvessel perfusion was quantified by video fluorescence microscopy at 0 and 90 min. To register interstitial edema, alveolar septal width was quantified. Pulmonary artery pressure (PAP), airway pressure, and left atrial pressure were recorded continuously. Lungs were randomly assigned to four groups (each n = 5): (i) control: no treatment, (ii) HEP1: heparinase I (1 mU/mL) was injected for GLX degradation, (iii) HES 130, and (iv) HES 200: one third of perfusion fluid was exchanged for 6% HES 130/0.4 or 10% HES 200/0.5 before GLX degradation. Analysis of variance on ranks and pairwise multiple comparisons were used for statistics, P < 0.05. Compared with control, GLX degradation effected perfusion failure in microvessels, increased PAP, and facilitated interstitial edema formation after a 90-min period of perfusion. In contrast to HES 200/0.5, pretreatment with HES 130/0.4 attenuated all of these consequences. Sequelae of GLX degradation in lung include perfusion failure in microvessels, interstitial edema formation, and increase in PAP. We assume that these effects are a consequence of vascular barrier dysfunction. Beneficial effects of HES 130/0.4 are presumably a result of its lower red blood cell bridging capacity compared with HES 200/0.5.

Objective: According to Fick's law of diffusion, gas exchange depends on the size and thickness of the blood perfused alveolocapillary membrane. Impairment of either one is tenuous. No data are available concerning the impact of hydroxyethyl starches and saline on pulmonary microperfusion and gas exchange during systemic inflammation. Design: Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects: Thirty-two anesthetized rabbits assigned to four groups (n = 8). Interventions: Except for the control group, systemic inflammation was induced by lipopolysaccharide. Fluid resuscitation was performed with saline alone or in conjunction with tetrastarch or pentastarch. Pulmonary microcirculation was analyzed at 0 hr and 2 hrs using intravital microscopy. Thickness of the alveolocapillary membrane was measured using electron microscopy. Measurements and Main Results: Macrohemodynamics were stable in all groups. In pulmonary arterioles, lipopolysaccharide reduced the erythrocyte velocity and impeded the microvascular decrease of the hematocrit in the saline and pentastarch group. In contrast, infusion of tetrastarch normalized these perfusion parameters. In capillaries, lipopolysaccharide decreased the functional capillary segment density and the capillary perfusion index, which was prevented by both starches. However, compared with saline and pentastarch, treatment with tetrastarch prevented the lipopolysaccharide-induced reduction of the capillary erythrocyte flux and inversely reduced the erythrocyte capillary transit time. Thickening of alveolocapillary septae after lipopolysaccharide application was solely observed in the saline and pentastarch group. In contrast to pentastarch and saline, the application of tetrastarch prevented the lipopolysaccharide-induced increase of the alveoloarterial oxygen difference. Conclusions: Tetrastarch sustains pulmonary gas exchange during experimental systemic inflammation more effectively than saline and pentastarch by protecting the diffusion distance and the size of the microvascular gas exchange surface. Improved capillary perfusion resulting from tetrastarch therapy, which is typically applied to increase blood pressure, may according to the Ohm's law locally decrease hydrostatic perfusion pressures in the pulmonary microvasculature during systemic inflammation.

Pulmonary perfusion disorders provoke atelectasis in order to minimize ventilation/perfusion mismatch. However, the underlying mechanisms remain unknown. Because intraalveolar CO2 concentration ([CO2]iA) declines as a consequence of poor pulmonary perfusion we postulated the existence a novel alveolar CO2-sensing mechanism which adapts the ventilation to perfusion. Real-time fluorescence imaging of rat lungs revealed that low [CO2]iA decreased cytosolic and increased mitochondrial Ca2+ in alveolar epithelial cells (AEC), leading to reduction of surfactant secretion and alveolar ventilation. Mitochondrial inhibition by ruthenium red or rotenone blocked the hypocapnia-induced responses. In cultured Type 2 AEC hypocapnia decreased cytosolic Ca2+ independently from pH and increased the NADH production, the mitochondrial transmembrane potential, and subsequently the mitochondrial Ca2+ uptake. All responses were completely blocked by the gene knockdown of the NADH producing Krebs cycle enzyme isocitrate dehydrogenase. Furthermore, ligature of the pulmonary artery of rabbits decreased alveolar ventilation, surfactant secretion, and lung compliance. Addition of 5% CO2 to the inspiratory gas inhibited all responses. Accordingly, we provide evidence for a novel CO2-sensing mechanism of AEC regulated by the Krebs cycle activity in terms of a negative feedback loop adapting surfactant secretion and thus regional ventilation to pulmonary perfusion.

Although the vascular bed is a major source of nitric oxide (NO) production, factors regulating the production remain unclear. We considered the role played by paracrine signaling. Determinations by fluorescence microscopy in isolated, blood-perfused rat and mouse lungs revealed that a brief lung expansion enhanced cytosolic Ca2+ (Ca2+cyt) oscillations in alveolar epithelial (AEC) and endothelial (EC) cells, and NO production in EC. Furthermore, as assessed by a novel microlavage assay, alveolar ATP production increased. Intra-alveolar microinfusion of the purinergic receptor antagonist, PPADS, and the nucleotide hydrolyzing enzyme, apyrase, each completely blocked the Ca2+cyt and NO responses in EC. Lung expansion induced Ca2+cyt oscillations in mice lacking the P2Y1, but not the P2Y2, purinergic receptors, which were located in the perivascular interstitium basolateral to AEC. Prolonged lung expansion instituted by mechanical ventilation at high tidal volume increased EC expression of nitrotyrosine, indicating development of nitrosative stress in lung microvessels. These findings reveal a novel mechanism in which mechanically induced purinergic signaling couples cross-compartmental Ca2+cyt oscillations to microvascular NO production.

ATP released from lung epithelial cells e.g. following mechanical ventilation mediates alveolar inflammatory responses. To determine mechanisms we considered an ATP-induced signaling from alveoli t...

Permeability of the endothelial barrier to large molecules plays a pivotal role in the manifestation of early acute lung injury. We present a novel and sensitive technique that brings microanatomical visualization and quantification of microvascular permeability in line. White New Zealand rabbits were anesthetized and ventilated mechanically. Rabbit serum albumin (RSA) was labeled with colloidal gold particles. We quantified macromolecular leakage of gold-labeled RSA and thickening of the gas exchange distance by electron microscopy, taking into account morphology of microvessels. The control group receiving a saline solution represented a normal gas exchange barrier without extravasation of gold-labeled albumin. Infusion of lipopolysaccharide (LPS) resulted in a significant displacement of gold-labeled albumin into pulmonary cells, the lung interstitium, and even the alveolar space. Correspondingly, intravital fluorescence microscopy and digital image analysis indicated thickening of width of alveolar septa. The findings were accompanied by a deterioration of alveolo-arterial oxygen difference, whereas wet/dry ratio and albumin concentration in the bronchoalveolar lavage fluid failed to detect that early stage of pulmonary edema. Inhibition of the nuclear enzyme poly(ADP-ribose) synthetase by 3-aminobenzamide prevented LPS-induced microvascular injury. To summarize: colloidal gold particles visualized by standard electron microscopy are a new and very sensitive in vivo marker of microvascular permeability in early acute lung injury. This technique enabling detailed microanatomical and quantitative pathophysiological characterization of edema formation can form the basis for evaluating novel treatment strategies against acute lung injury.

Excessive nitric oxide (NO) and especially peroxynitrite may cause pulmonary tissue damage, e.g., through lipid peroxidation and/or exhaustion of cellular energy depletion induced by activation of poly (ADP-ribose) polymerase (PARP). Furthermore, PARP seems to aggravate tissue destruction by regulating the expression of respective genes.Prospective animal study.University research laboratory.We investigated the effect of competitive PARP inhibition by 3-aminobenzamide (3-AB) on the pulmonary iNOS pathway after infusion of lipopolysaccharide (LPS).The pretreatment of rabbits with 3-AB attenuated the LPS-induced iNOS mRNA and protein expression analyzed by RT-PCR and Western blot, and plasma nitrite concentrations quantified by Griess reaction (71+/-6%, 93+/-6% vs baseline). Electromobility shift assay showed an enhanced NF-kappaB and attenuated AP-1 activation after 3-AB vs LPS alone. Lipid peroxidation determined as levels of thiobarbituric acid reactive substances in plasma and lung tissue was reduced by 50% in the LPS+3-AB in comparison to LPS alone. Simultaneously, 3-AB was able to inhibit correspondingly the LPS-induced extravasation of gold-labeled albumin and increase of alveolo-arterial oxygen difference.PARP regulates the pulmonary NO pathway during endotoxemia via AP-1 and not NF-kappaB. Thus, pharmacological inhibition of PARP might be an effective intervention to prevent endotoxin-induced lung injury, interrupting the vicious circle of NO production and PARP activation.

Edema formation is the first manifestation of acute pancreatitis. Microcirculatory derangements like leukocyte-endothelial cell interaction and perfusion failure result in enhancement of microvascular permeability to large molecules playing a pivotal role in the progression of the acutely altered pancreatic tissue. Due to the lack of suitable methods the crucial mechanisms of enhanced permeability in vivo are not very well investigated. Sprague-Dawley rats were randomly assigned to three groups: (a) sham operated animals with normal pancreas, (b) the pancreatitis group induced by 60 min temporary occlusion of the arterial supply followed by reperfusion and (c) the histamine group in which the pancreas was superfused with 10(-5)M histamine. The pharmacokinetics of tetramethylrhodamine-labelled BSA in the intravital microscopic images of a capillary network of the pancreas were densitometrically quantified over 20 min. From these data the effective microvascular permeability was calculated taking also into account morphology of microvessels, elimination rate of the tracer from the intravascular space and capillary microhematocrit. In addition macromolecular leakage of gold-labelled BSA was investigated by electron microscopy. Microvascular permeability was 0.10 +/- 0.02 x 10(-7) cm/s, 0.49 +/- 0.04 x 10(-7) cm/s and 1.21 +/- 0.29 x 10(-7) cm/s for control, ischemia and histamine group, respectively (P0.05 ischemia, histamine vs. control and ischemia vs. histamine). Electron microscopy revealed albumin extravasation in the last two groups. We established a technique allowing to quantify microvascular permeability in pancreatic tissue by dynamic intravital microscopy being independent of the investigator. This technique enabling accurate pathophysiologic characterisation in terms of edema formation can form the basis for evaluating in the future novel treatment strategies directed against acute pancreatitis.

During systemic inflammation, recruitment and activation of leukocytes in the pulmonary microcirculation may result in a potentially life-threatening acute lung injury. We elucidated the role of the poly(ADP-ribose) synthetase (PARS), a nucleotide-polymerizing enzyme, in the regulation of leukocyte recruitment within the lung with regard to the localization in the pulmonary microcirculation and in correlation to hemodynamics in the respective vascular segments and expression of intercellular adhesion molecule 1 during endotoxemia. Inhibition of PARS by 3-aminobenzamide reduced the endotoxin-induced leukocyte recruitment within pulmonary arterioles, capillaries, and venules in rabbits as quantified by in vivo fluorescence microscopy. Microhemodynamics and thus shear rates in all pulmonary microvascular segments remained constant. Simultaneously, inhibition of PARS with 3-aminobenzamide suppressed the endotoxin-induced adhesion molecules expression as demonstrated for intercellular adhesion molecule 1 by immunohistochemistry and Western blot analysis. We confirmed this result with the use of PARS knockout mice. The inhibitory effect of 3-aminobenzamide on leukocyte recruitment was associated with a reduction of pulmonary capillary leakage and edema formation. We first provide evidence that PARS activation mediates the leukocyte sequestration in pulmonary microvessels through upregulation of adhesion molecules. As reactive oxygen species released from leukocyte are supposed to cause an upregulation of adhesion molecules we conclude that PARS inhibition contributes to termination of this vicious cycle and inhibits the inflammatory process.