TY - JOUR A1 - Burek, Malgorzata A1 - Burmester, Sandra A1 - Salvador, Ellaine A1 - Möller-Ehrlich, Kerstin A1 - Schneider, Reinhard A1 - Roewer, Norbert A1 - Nagai, Michiaki A1 - Förster, Carola Y. T1 - Kidney Ischemia/Reperfusion Injury Induces Changes in the Drug Transporter Expression at the Blood–Brain Barrier in vivo and in vitro JF - Frontiers in Physiology N2 - Ischemia/reperfusion injury is a major cause of acute kidney injury (AKI). AKI is characterized by a sudden decrease in kidney function, systemic inflammation, oxidative stress, and dysregulation of the sodium, potassium, and water channels. While AKI leads to uremic encephalopathy, epidemiological studies have shown that AKI is associated with a subsequent risk for developing stroke and dementia. To get more insights into kidney–brain crosstalk, we have created an in vitro co-culture model based on human kidney cells of the proximal tubule (HK-2) and brain microvascular endothelial cells (BMEC). The HK-2 cell line was grown to confluence on 6-well plates and exposed to oxygen/glucose deprivation (OGD) for 4 h. Control HK-2 cells were grown under normal conditions. The BMEC cell line cerebED was grown to confluence on transwells with 0.4 μm pores. The transwell filters seeded and grown to confluence with cereEND were inserted into the plates with HK-2 cells with or without OGD treatment. In addition, cerebEND were left untreated or treated with uremic toxins, indole-3-acetic acid (IAA) and indoxyl sulfate (IS). The protein and mRNA expression of selected BBB-typical influx transporters, efflux transporters, cellular receptors, and tight junction proteins was measured in BMECs. To validate this in vitro model of kidney–brain interaction, we isolated brain capillaries from mice exposed to bilateral renal ischemia (30 min)/reperfusion injury (24 h) and measured mRNA and protein expression as described above. Both in vitro and in vivo systems showed similar changes in the expression of drug transporters, cellular receptors, and tight junction proteins. Efflux pumps, in particular Abcb1b, Abcc1, and Abcg2, have shown increased expression in our model. Thus, our in vitro co-culture system can be used to study the cellular mechanism of kidney and brain crosstalk in renal ischemia/reperfusion injury. KW - kidney ischemia/reperfusion injury KW - brain pathology KW - blood–brain barrier KW - drug transporter KW - tight junctions Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216413 SN - 1664-042X VL - 11 ER - TY - JOUR A1 - Curtaz, Carolin J. A1 - Schmitt, Constanze A1 - Herbert, Saskia-Laureen A1 - Feldheim, Jonas A1 - Schlegel, Nicolas A1 - Gosselet, Fabien A1 - Hagemann, Carsten A1 - Roewer, Norbert A1 - Meybohm, Patrick A1 - Wöckel, Achim A1 - Burek, Malgorzata T1 - Serum-derived factors of breast cancer patients with brain metastases alter permeability of a human blood-brain barrier model JF - Fluids and Barriers of the CNS N2 - Background The most threatening metastases in breast cancer are brain metastases, which correlate with a very poor overall survival, but also a limited quality of life. A key event for the metastatic progression of breast cancer into the brain is the migration of cancer cells across the blood-brain barrier (BBB). Methods We adapted and validated the CD34\(^+\) cells-derived human in vitro BBB model (brain-like endothelial cells, BLECs) to analyse the effects of patient serum on BBB properties. We collected serum samples from healthy donors, breast cancer patients with primary cancer, and breast cancer patients with, bone, visceral or cerebral metastases. We analysed cytokine levels in these sera utilizing immunoassays and correlated them with clinical data. We used paracellular permeability measurements, immunofluorescence staining, Western blot and mRNA analysis to examine the effects of patient sera on the properties of BBB in vitro. Results The BLECs cultured together with brain pericytes in transwells developed a tight monolayer with a correct localization of claudin-5 at the tight junctions (TJ). Several BBB marker proteins such as the TJ proteins claudin-5 and occludin, the glucose transporter GLUT-1 or the efflux pumps PG-P and BCRP were upregulated in these cultures. This was accompanied by a reduced paracellular permeability for fluorescein (400 Da). We then used this model for the treatment with the patient sera. Only the sera of breast cancer patients with cerebral metastases had significantly increased levels of the cytokines fractalkine (CX3CL1) and BCA-1 (CXCL13). The increased levels of fractalkine were associated with the estrogen/progesterone receptor status of the tumour. The treatment of BLECs with these sera selectively increased the expression of CXCL13 and TJ protein occludin. In addition, the permeability of fluorescein was increased after serum treatment. Conclusion We demonstrate that the CD34\(^+\) cell-derived human in vitro BBB model can be used as a tool to study the molecular mechanisms underlying cerebrovascular pathologies. We showed that serum from patients with cerebral metastases may affect the integrity of the BBB in vitro, associated with elevated concentrations of specific cytokines such as CX3CL1 and CXCL13. KW - Metastatic breast cancer KW - Blood–brain barrier KW - In vitro models KW - CX3CL1 KW - CXCL13 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229940 VL - 17 ER - TY - JOUR A1 - Lehmann, Martin A1 - Oehler, Beatrice A1 - Zuber, Jonas A1 - Malzahn, Uwe A1 - Walles, Thorsten A1 - Muellenbach, Ralf M. A1 - Roewer, Norbert A1 - Kredel, Markus T1 - Redistribution of pulmonary ventilation after lung surgery detected with electrical impedance tomography JF - Acta Anaesthesiologica Scandinavica N2 - Background: Regional ventilation of the lung can be visualized by pulmonary electrical impedance tomography (EIT). The aim of this study was to examine the post‐operative redistribution of regional ventilation after lung surgery dependent on the side of surgery and its association with forced vital capacity. Methods: In this prospective, observational cohort study 13 patients undergoing right and 13 patients undergoing left‐sided open or video‐thoracoscopic procedures have been investigated. Pre‐operative measurements with EIT and spirometry were compared with data obtained 3 days post‐operation. The center of ventilation (COV) within a 32 × 32 pixel matrix was calculated from EIT data. The transverse axis coordinate of COV, COVx (left/right), was modified to COVx′ (ipsilateral/contralateral). Thus, COVx′ shows a negative change if ventilation shifts contralateral independent of the side of surgery. This enabled testing with two‐way ANOVA for repeated measurements (side, time). Results: The perioperative shift of COVx′ was dependent on the side of surgery (P = .007). Ventilation shifted away from the side of surgery after the right‐sided surgery (COVx′‐1.97 pixel matrix points, P < .001), but not after the left‐sided surgery (COVx′‐0.61, P = .425). The forced vital capacity (%predicted) decreased from 94 (83‐109)% (median [quartiles]; [left‐sided]) and 89 (80‐97)% (right‐sided surgery) to 61 (59‐66)% and 62 (40‐72)% (P < .05), respectively. The perioperative changes in forced vital capacity (%predicted) were weakly associated with the shift of COVx′. Conclusion: Only after right‐sided lung surgery, EIT showed reduced ventilation on the side of surgery while vital capacity was markedly reduced in both groups. KW - electrical impedance tomography KW - general anaesthesia KW - one‐lung ventilation KW - postoperative complications KW - pulmonary function tests KW - pulmonary surgical procedures Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213575 VL - 64 IS - 4 ER - TY - JOUR A1 - Bauer, Maria A1 - Opitz, Anne A1 - Filser, Jörg A1 - Jansen, Hendrik A1 - Meffert, Rainer H. A1 - Germer, Christoph T. A1 - Roewer, Norbert A1 - Muellenbach, Ralf M. A1 - Kredel, Markus T1 - Perioperative redistribution of regional ventilation and pulmonary function: a prospective observational study in two cohorts of patients at risk for postoperative pulmonary complications JF - BMC Anesthesiology N2 - Background Postoperative pulmonary complications (PPCs) increase morbidity and mortality of surgical patients, duration of hospital stay and costs. Postoperative atelectasis of dorsal lung regions as a common PPC has been described before, but its clinical relevance is insufficiently examined. Pulmonary electrical impedance tomography (EIT) enables the bedside visualization of regional ventilation in real-time within a transversal section of the lung. Dorsal atelectasis or effusions might cause a ventral redistribution of ventilation. We hypothesized the existence of ventral redistribution in spontaneously breathing patients during their recovery from abdominal and peripheral surgery and that vital capacity is reduced if regional ventilation shifts to ventral lung regions. Methods This prospective observational study included 69 adult patients undergoing elective surgery with an expected intermediate or high risk for PPCs. Patients undergoing abdominal and peripheral surgery were recruited to obtain groups of equal size. Patients received general anesthesia with and without additional regional anesthesia. On the preoperative, the first and the third postoperative day, EIT was performed at rest and during spirometry (forced breathing). The center of ventilation in dorso-ventral direction (COVy) was calculated. Results Both groups received intraoperative low tidal volume ventilation. Postoperative ventral redistribution of ventilation (forced breathing COVy; preoperative: 16.5 (16.0–17.3); first day: 17.8 (16.9–18.2), p < 0.004; third day: 17.4 (16.2–18.2), p = 0.020) and decreased forced vital capacity in percentage of predicted values (FVC%predicted) (median: 93, 58, 64%, respectively) persisted after abdominal surgery. In addition, dorsal to ventral shift was associated with a decrease of the FVC%predicted on the third postoperative day (r = − 0.66; p < 0.001). A redistribution of pulmonary ventilation was not observed after peripheral surgery. FVC%predicted was only decreased on the first postoperative day (median FVC%predicted on the preoperative, first and third day: 85, 81 and 88%, respectively). In ten patients occurred pulmonary complications after abdominal surgery also in two patients after peripheral surgery. Conclusions After abdominal surgery ventral redistribution of ventilation persisted up to the third postoperative day and was associated with decreased vital capacity. The peripheral surgery group showed only minor changes in vital capacity, suggesting a role of the location of surgery for postoperative redistribution of pulmonary ventilation. KW - Electrical impedance tomography KW - General anaesthesia KW - Postoperative complications KW - Pulmonary function tests Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200730 VL - 19 ER - TY - JOUR A1 - Schuster, Frank A1 - Johannsen, Stephan A1 - Isbary, Susanne A1 - Türkmeneli, Ismail A1 - Roewer, Norbert T1 - In vitro effects of levosimendan on muscle of malignant hyperthermia susceptible and non-susceptible swine JF - BMC Anesthesiology N2 - Background: The calcium sensitizer levosimendan is increasingly used to improve hemodynamics in patients with acutely decompensated heart failure. By binding to cardiac troponin C the conformation of the calcium-troponin C complex is stabilized, which leads to acceleration of actin-myosin crossbrigde formation and increased force generating capacity of muscle fibers. Besides indications in cardiac failure, beneficial effects of levosimendan in skeletal muscle disorders are currently evaluated. The aim of this study was to investigate differential effects of levosimendan on skeletal muscle of pigs with and without susceptibility to malignant hyperthermia (MH) in order to identify possible risks of this emerging drug for patients with predisposition to MH. Methods: Muscle bundles of 17 pigs (9 MH susceptible (MHS); 8 MH non-susceptible (MHN)) were excised under general anesthesia and examined in the tissue bath with increasing concentrations of levosimendan (0.065; 0.125; 0.5; 1.0; 10 and 50 μg/ml). Baseline tension and twitch force were monitored continuously. Data are presented as median and interquartile range. Statistical evaluation was performed using D’Agostino & Pearson test for normal distribution and student’s t test and 2-way ANOVA for differences between the groups. P < 0.05 was considered significant. Results: There were no differences between the groups concerning length, weight, initial twitch force and pre-drug resting tension of the investigated muscle strips. After an initial decrease in both groups, twitch amplitude was significantly higher in MHN (− 3.0 [− 5.2–0.2] mN) compared to MHS (− 7.5 [− 10.8- -4.5] mN) (p = 0.0034) muscle at an applied levosimendan concentration of 50 μg/ml. A marked increase in resting tension was detected following levosimendan incubation with 50 μg/ml in MHS muscle bundles (3.3 [0.9–6.1] mN) compared to MHN (− 0.7 [− 1.3–0.0] mN) (p < 0.0001). Conclusions: This in vitro investigation revealed the development of significant contractures in muscle bundles of MHS pigs after incubation with levosimendan. However, the effect appeared only at supra-therapeutic concentrations and further research is needed to determine the impact of levosimendan on MHS individuals in vivo. KW - malignant hyperthermia KW - levosimendan KW - muscle KW - pigs KW - in vitro contracture test Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176991 VL - 18 IS - 182 ER - TY - JOUR A1 - Chen, Shasha A1 - Lotz, Christopher A1 - Roewer, Norbert A1 - Broscheit, Jens-Albert T1 - Comparison of volatile anesthetic-induced preconditioning in cardiac and cerebral system: molecular mechanisms and clinical aspects JF - European Journal of Medical Research N2 - Volatile anesthetic-induced preconditioning ( APC) has shown to have cardiac and cerebral protective properties in both pre-clinical models and clinical trials. Interestingly, accumulating evidences demonstrate that, except from some specific characters, the underlying molecular mechanisms of APC-induced protective effects in myocytes and neurons are very similar; they share several major intracellular signaling pathways, including mediating mitochondrial function, release of inflammatory cytokines and cell apoptosis. Among all the experimental results, cortical spreading depolarization is a relative newly discovered cellular mechanism of APC, which, however, just exists in central nervous system. Applying volatile anesthetic preconditioning to clinical practice seems to be a promising cardio- and neuroprotective strategy. In this review, we also summarized and discussed the results of recent clinical research of APC. Despite all the positive experimental evidences, large-scale, long-term, more precisely controlled clinical trials focusing on the perioperative use of volatile anesthetics for organ protection are still needed. KW - APC KW - ischemia-reperfusion injury KW - mitochondria KW - apoptosis Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175509 VL - 23 IS - 10 ER - TY - JOUR A1 - Johannsen, Stephan A1 - Schick, Martin A1 - Roewer, Norbert A1 - Schuster, Frank T1 - Microdialysis and ultrasound elastography for monitoring of localized muscular reaction after pharmacological stimulation in rats JF - BMC Research Notes N2 - Objective: Halothane and caffeine are known to cause skeletal muscular contractions in vitro and have been proven to induce circumscribed metabolic reactions when injected into rat skeletal muscle. In this study 26 rats were investigated by either continuous application of calcium 160 mM or bolus injection of caffeine 160 mM or halothane 10% vol via a microdialysis probe in the tibialis anterior muscle. Tissue elasticity at the injection site was monitored by ultrasound strain elastography. Aim of this study was to detect (I) changes in local lactate concentrations and (II) whether these can be attributed to a muscular contraction detected by ultrasound elastography. Results: Localized metabolic reactions were verified by increasing intramuscular lactate concentrations following continuous application of calcium (0.6 [0.3;0.6] to 3.6 [3.0;4.3] mmol/l after 60 min) and bolus application of caffeine (0.2 [0.2;0.3] to 1.6 [0.9;1.9] mmol/l after 30 min) and halothane (0.3 [0.1;0.3] to 4.7 [4.3;6.3] mmol/l after 30 min). However, ultrasound elastography did not detect any differences in tissue elasticity compared to control animals. The authors identified potential limitations of the study conditions, which might be crucial to avoid for future investigations. KW - skeletal muscle KW - ultrasound strain elastography KW - microdialysis KW - halothane KW - caffeine Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176977 VL - 11 IS - 636 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Roewer, Norbert A1 - Förster, Carola A1 - Broscheit, Jens-Albert T1 - In silico modeling of indigo and Tyrian purple single-electron nano-transistors using density functional theory approach JF - Nanoscale Research Letters N2 - The purpose of this study was to develop and implement an in silico model of indigoid-based single-electron transistor (SET) nanodevices, which consist of indigoid molecules from natural dye weakly coupled to gold electrodes that function in a Coulomb blockade regime. The electronic properties of the indigoid molecules were investigated using the optimized density-functional theory (DFT) with a continuum model. Higher electron transport characteristics were determined for Tyrian purple, consistent with experimentally derived data. Overall, these results can be used to correctly predict and emphasize the electron transport functions of organic SETs, demonstrating their potential for sustainable nanoelectronics comprising the biodegradable and biocompatible materials. KW - density functional theory KW - indigo KW - Tyrian purple KW - single-electron transistor Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158332 VL - 12 IS - 439 ER - TY - JOUR A1 - Kredel, Markus A1 - Kunzmann, Steffen A1 - Schlegel, Paul-Gerhardt A1 - Wölfl, Matthias A1 - Nordbeck, Peter A1 - Bühler, Christoph A1 - Lotz, Christopher A1 - Lepper, Philipp M. A1 - Wirbelauer, Johannes A1 - Roewer, Norbert A1 - Muellenbach, Ralf M. T1 - Double Peripheral Venous and Arterial Cannulation for Extracorporeal Membrane Oxygenation in Combined Septic and Cardiogenic Shock JF - American Journal of Case Reports N2 - Background: The use of venoarterial extracorporeal membrane oxygenation (va-ECMO) via peripheral cannulation for septic shock is limited by blood flow and increased afterload for the left ventricle. Case Report: A 15-year-old girl with acute myelogenous leukemia, suffering from severe septic and cardiogenic shock, was treated by venoarterial extracorporeal membrane oxygenation (va-ECMO). Sufficient extracorporeal blood flow matching the required oxygen demand could only be achieved by peripheral cannulation of both femoral arteries. Venous drainage was performed with a bicaval cannula inserted via the left V. femoralis. To accomplish left ventricular unloading, an additional drainage cannula was placed in the left atrium via percutaneous atrioseptostomy (va-va-ECMO). Cardiac function recovered and the girl was weaned from the ECMO on day 6. Successful allogenic stem cell transplantation took place 2 months later. Conclusions: In patients with vasoplegic septic shock and impaired cardiac contractility, double peripheral venoarterial extracorporeal membrane oxygenation (va-va-ECMO) with transseptal left atrial venting can by a lifesaving option. KW - extracorporeal membrane oxygenation KW - myeloid KW - leukemia KW - acute KW - shock KW - cardiogenic KW - septic Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158193 VL - 18 ER - TY - JOUR A1 - Schick, Martin Alexander A1 - Baar, Wolfgang A1 - Bruno, Raphael Romano A1 - Wollborn, Jakob A1 - Held, Christopher A1 - Schneider, Reinhard A1 - Flemming, Sven A1 - Schlegel, Nicolas A1 - Roewer, Norbert A1 - Neuhaus, Winfried A1 - Wunder, Christian T1 - Balanced hydroxyethylstarch (HES 130/0.4) impairs kidney function in-vivo without inflammation JF - PLoS One N2 - Volume therapy is a standard procedure in daily perioperative care, and there is an ongoing discussion about the benefits of colloid resuscitation with hydroxyethylstarch (HES). In sepsis HES should be avoided due to a higher risk for acute kidney injury (AKI). Results of the usage of HES in patients without sepsis are controversial. Therefore we conducted an animal study to evaluate the impact of 6% HES 130/0.4 on kidney integrity with sepsis or under healthy conditions Sepsis was induced by standardized Colon Ascendens Stent Peritonitis (sCASP). sCASP-group as well as control group (C) remained untreated for 24 h. After 18 h sCASP+HES group (sCASP+VOL) and control+HES (C+VOL) received 50 ml/KG balanced 6% HES (VOL) 130/0.4 over 6h. After 24h kidney function was measured via Inulin- and PAH-Clearance in re-anesthetized rats, and serum urea, creatinine (crea), cystatin C and Neutrophil gelatinase-associated lipocalin (NGAL) as well as histopathology were analysed. In vitro human proximal tubule cells (PTC) were cultured +/- lipopolysaccharid (LPS) and with 0.1–4.0% VOL. Cell viability was measured with XTT-, cell toxicity with LDH-test. sCASP induced severe septic AKI demonstrated divergent results regarding renal function by clearance or creatinine measure focusing on VOL. Soleley HES (C+VOL) deteriorated renal function without sCASP. Histopathology revealed significantly derangements in all HES groups compared to control. In vitro LPS did not worsen the HES induced reduction of cell viability in PTC cells. For the first time, we demonstrated, that application of 50 ml/KG 6% HES 130/0.4 over 6 hours induced AKI without inflammation in vivo. Severity of sCASP induced septic AKI might be no longer susceptible to the way of volume expansion KW - colloids KW - kidneys KW - histopathology KW - blood KW - creatinine KW - sepsis KW - urine KW - inflammation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126068 VL - 10 IS - 9 ER - TY - JOUR A1 - Wurmb, Thomas A1 - Vollmer, Tina A1 - Sefrin, Peter A1 - Kraus, Martin A1 - Happel, Oliver A1 - Wunder, Christian A1 - Steinisch, Andrias A1 - Roewer, Norbert A1 - Maier, Sebastian T1 - Monitoring of in-hospital cardiac arrest events with the focus on Automated External Defibrillators – a retrospective observational study JF - Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine N2 - Background Patients with cardiac arrest have lower survival rates, when resuscitation performance is low. In In-hospital settings the first responders on scene are usually nursing staff without rhythm analysing skills. In such cases Automated External Defibrillators (AED) might help guiding resuscitation performance. At the Wuerzburg University Hospital (Germany) an AED-program was initiated in 2007. Aim of the presented study was to monitor the impact of Automated External Defibrillators on the management of in-hospital cardiac arrest events. Methods The data acquisition was part of a continuous quality improvement process of the Wuerzburg University Hospital. For analysing the CPR performance, the chest compression rate (CCR), compression depth (CCD), the no flow fraction (NFF), time interval from AED-activation to the first compression (TtC), the time interval from AED-activation to the first shock (TtS) and the post schock pause (TtCS) were determined by AED captured data. A questionnaire was completed by the first responders. Results From 2010 to 2012 there were 359 emergency calls. From these 53 were cardiac arrests with an AED-application. Complete data were available in 46 cases. The TtC was 34 (32–52) seconds (median and IQR).The TtS was 30 (28–32) seconds (median and IQR) . The TtCS was 4 (3–6) seconds (median and IQR) . The CCD was 5.5 ± 1 cm while the CCR was 107 ± 11/min. The NFF was calculated as 41 %. ROSC was achieved in 21 patients (45 %), 8 patients (17 %) died on scene and 17 patients (37 %) were transferred under ongoing CPR to an Intensive Care Unit (ICU). Conclusion The TtS and TtC indicate that there is an AED-user dependent time loss. These time intervals can be markedly reduced, when the user is trained to interrupt the AED’s “chain of advices” by placing the electrode-paddles immediately on the patient’s thorax. At this time the AED switches directly to the analysing mode. Intensive training and adaption of the training contents is needed to optimize the handling of the AED in order to maximize its advantages and to minimize its disadvantages. KW - cardio-pulmonary resuscitation KW - team-training KW - chest-compression rate KW - automated external defibrillators KW - in-hospital cardiac arrest Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125756 VL - 23 IS - 87 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Puskás, István A1 - Pápai, Katalin A1 - Salvador, Ellaine A1 - Roewer, Norbert A1 - Förster, Carola A1 - Broscheit, Jens-Albert T1 - Sevoflurane-sulfobutylether-\(\beta\)-cyclodextrin complex: preparation, characterization, cellular toxicity, molecular modeling and blood-brain barrier transport studies JF - Molecules N2 - The objective of the present investigation was to study the ability of sulfobutylether-\(\beta\)-cyclodextrin (SBECD) to form an inclusion complex with sevoflurane (SEV), a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB) permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBE\(\beta\)CD complex was nontoxic to the primary brain microvascular endothelial (pEND) cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol) concerning calculated apparent permeability values (P\(_{app}\)). In addition, SEV binding affinity to SBE\(\beta\)CD was confirmed by a minimal Gibbs free energy of binding (ΔG\(_{bind}\)) value of -1.727 ± 0.042 kcal・mol\(^{-1}\) and an average binding constant (K\(_{b}\)) of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity. KW - pharmaceutical applications KW - in vitro KW - propranolol KW - water KW - primary microvascular endothelial cells KW - molecular liphophilicity potential KW - molecular docking KW - blood-brain barrier KW - ulfobutylether-\(\beta\)-cyclodextrin KW - sevoflurane KW - cyclodextrin formulations KW - safety KW - etomidate KW - formulations KW - hydrochloride KW - ether KW - intestinal absorption Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148543 VL - 20 ER - TY - JOUR A1 - Wollborn, Jakob A1 - Wunder, Christian A1 - Stix, Jana A1 - Neuhaus, Winfried A1 - Bruno, Rapahel R. A1 - Baar, Wolfgang A1 - Flemming, Sven A1 - Roewer, Norbert A1 - Schlegel, Nicolas A1 - Schick, Martin A. T1 - Phosphodiesterase-4 inhibition with rolipram attenuates hepatocellular injury in hyperinflammation in vivo and in vitro without influencing inflammation and HO-1 expression JF - Journal of Pharmacology and Pharmacotherapeutics N2 - Objective: To investigate the impact of the phophodiesterase-4 inhibition (PD-4-I) with rolipram on hepatic integrity in lipopolysaccharide (LPS) induced hyperinflammation. Materials and Methods: Liver microcirculation in rats was obtained using intravital microscopy. Macrohemodynamic parameters, blood assays, and organs were harvested to determine organ function and injury. Hyperinflammation was induced by LPS and PD-4-I rolipram was administered intravenously one hour after LPS application. Cell viability of HepG2 cells was measured by EZ4U-kit based on the dye XTT. Experiments were carried out assessing the influence of different concentrations of tumor necrosis factor alpha (TNF-α) and LPS with or without PD-4-I. Results: Untreated LPS-induced rats showed significantly decreased liver microcirculation and increased hepatic cell death, whereas LPS + PD-4-I treatment could improve hepatic volumetric flow and cell death to control level whithout influencing the inflammatory impact. In HepG2 cells TNF-α and LPS significantly reduced cell viability. Coincubation with PD-4-I increased HepG2 viability to control levels. The heme oxygenase 1 (HO-1) pathway did not induce the protective effect of PD-4-I. Conclusion: Intravenous PD-4-I treatment was effective in improving hepatic microcirculation and hepatic integrity, while it had a direct protective effect on HepG2 viability during inflammation. KW - acute liver failure KW - endotoxemia KW - phosphodiesterase KW - rolipram KW - sepsis Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149336 VL - 6 IS - 1 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Sohajda, Tamás A1 - Puskas, Istaván A1 - Roewer, Norbert A1 - Förster, Carola A1 - Broscheit, Jens-Albert T1 - Ionization States, Cellular Toxicity and Molecular Modeling Studies of Midazolam Complexed with Trimethyl-β-Cyclodextrin JF - Molecules N2 - We investigated the ionization profiles for open-ring (OR) and closed-ring (CR) forms of midazolam and drug-binding modes with heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (trimethyl-β-cyclodextrin; TRIMEB) using molecular modeling techniques and quantum mechanics methods. The results indicated that the total net charges for different molecular forms of midazolam tend to be cationic for OR and neutral for CR at physiological pH levels. The thermodynamic calculations demonstrated that CR is less water-soluble than OR, mainly due to the maximal solvation energy (ΔG(CR)(solv = -9.98 kcal·mol ⁻¹), which has a minimal ΔG(OR)(solv) of -67.01 kcal·mol⁻¹. A cell viability assay did not detect any signs of TRIMEB and OR/CR-TRIMEB complex toxicity on the cEND cells after 24 h of incubation in either Dulbecco's Modified Eagles Medium or in heat-inactivated human serum. The molecular docking studies identified the more flexible OR form of midazolam as being a better binder to TRIMEB with the fluorophenyl ring introduced inside the amphiphilic cavity of the host molecule. The OR binding affinity was confirmed by a minimal Gibbs free energy of binding (ΔG(bind)) value of -5.57 ± 0.02 kcal·mol⁻¹, an equilibrium binding constant (K(b)) of 79.89 ± 2.706 μM, and a ligand efficiency index (LE(lig)) of -0.21 ± 0.001. Our current data suggest that in order to improve the clinical applications of midazolam via its complexation with trimethyl-β-cyclodextrin to increase drug's overall aqueous solubility, it is important to concern the different forms and ionization states of this anesthetic. All mean values are indicated with their standard deviations. KW - quantum mechanics KW - free energy of solvation KW - torsional energy KW - trimethyl-β-cyclodextrin KW - midazolam KW - transition state KW - molecular docking KW - Gibbs free energy of binding Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119186 VL - 19 IS - 10 ER - TY - JOUR A1 - Schick, Martin A. A1 - Baar, Wolfgang A1 - Flemming, Sven A1 - Schlegel, Nicolas A1 - Wollborn, Jakob A1 - Held, Christopher A1 - Schneider, Reinhard A1 - Brock, Robert W. A1 - Roewer, Norbert A1 - Wunder, Christian T1 - Sepsis-induced acute kidney injury by standardized colon ascendens stent peritonitis in rats - a simple, reproducible animal model JF - Intensive Care Medicine Experimental N2 - Background Up to 50% of septic patients develop acute kidney injury (AKI). The pathomechanism of septic AKI is poorly understood. Therefore, we established an innovative rodent model to characterize sepsis-induced AKI by standardized colon ascendens stent peritonitis (sCASP). The model has a standardized focus of infection, an intensive care set up with monitoring of haemodynamics and oxygenation resulting in predictable impairment of renal function, AKI parameters as well as histopathology scoring. Methods Anaesthetized rats underwent the sCASP procedure, whereas sham animals were sham operated and control animals were just monitored invasively. Haemodynamic variables and blood gases were continuously measured. After 24 h, animals were reanesthetized; cardiac output (CO), inulin and PAH clearances were measured and later on kidneys were harvested; and creatinine, urea, cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) were analysed. Additional sCASP-treated animals were investigated after 3 and 9 days. Results All sCASP-treated animals survived, whilst ubiquitous peritonitis and significantly deteriorated clinical and macrohaemodynamic sepsis signs after 24 h (MAP, CO, heart rate) were obvious. Blood analyses showed increased lactate and IL-6 levels as well as leucopenia. Urine output, inulin and PAH clearance were significantly decreased in sCASP compared to sham and control. Additionally, significant increase in cystatin C and NGAL was detected. Standard parameters like serum creatinine and urea were elevated and sCASP-induced sepsis increased significantly in a time-dependent manner. The renal histopathological score of sCASP-treated animals deteriorated after 3 and 9 days. Conclusions The presented sCASP method is a standardized, reliable and reproducible method to induce septic AKI. The intensive care set up, continuous macrohaemodynamic and gas exchange monitoring, low mortality rate as well as the opportunity of detailed analyses of kidney function and impairments are advantages of this setup. Thus, our described method may serve as a new standard for experimental investigations of septic AKI. KW - CASP KW - animal model KW - acute kidney injury KW - sepsis Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126111 VL - 2 IS - 34 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Puskás, István A1 - Roewer, Norbert A1 - Förster, Carola A1 - Broscheit, Jens T1 - Three-dimensional quantitative structure-activity relationship and docking studies in a series of anthocyanin derivatives as cytochrome P450 3A4 inhibitors JF - Advances and Applications in Bioinformatics and Chemistry N2 - The cytochrome P450 (CYP)3A4 enzyme affects the metabolism of most drug-like substances, and its inhibition may influence drug safety. Modulation of CYP3A4 by flavonoids, such as anthocyanins, has been shown to inhibit the mutagenic activity of mammalian cells. Considering the previous investigations addressing CYP3A4 inhibition by these substances, we studied the three-dimensional quantitative structure-activity relationship (3D-QSAR) in a series of anthocyanin derivatives as CYP3A4 inhibitors. For the training dataset (n=12), comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) yielded crossvalidated and non-crossvalidated models with a q (2) of 0.795 (0.687) and r (2) of 0.962 (0.948), respectively. The models were also validated by an external test set of four compounds with r (2) of 0.821 (CoMFA) and r (2) of 0.812 (CoMSIA). The binding affinity modes associated with experimentally derived IC50 (half maximal inhibitory concentration) values were confirmed by molecular docking into the CYP3A4 active site with r (2) of 0.66. The results obtained from this study are useful for a better understanding of the effects of anthocyanin derivatives on inhibition of carcinogen activation and cellular DNA damage. KW - molecular docking KW - three-dimensional quantitative structure–activity relationship KW - cytochrome P450 3A4 KW - comparative molecular similarity index analysis KW - comparative molecular field analysis KW - carcinogen activation KW - anthocyanin derivatives Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120226 VL - 7 ER - TY - JOUR A1 - Wurmb, Thomas Erik A1 - Schlereth, Stefan A1 - Kredel, Markus A1 - Muellenbach, Ralf M. A1 - Wunder, Christian A1 - Brederlau, Jörg A1 - Roewer, Norbert A1 - Kenn, Werner A1 - Kunze, Ekkehard T1 - Routine Follow-Up Cranial Computed Tomography for Deeply Sedated, Intubated, and Ventilated Multiple Trauma Patients with Suspected Severe Head Injury JF - BioMed Research International N2 - Background. Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may have negative impact on the outcome. We investigated whether routine follow-up CT is beneficial in sedated and mechanically ventilated trauma patients. Methods. The study design is a retrospective chart review. A routine follow-up cCT was performed 6 hours after the admission scan. We defined 2 groups of patients, group I: patients with equal or recurrent pathologies and group II: patients with new findings or progression of known pathologies. Results. A progression of intracranial injury was found in 63 patients (42%) and 18 patients (12%) had new findings in cCT 2 (group II). In group II a change in therapy was found in 44 out of 81 patients (54%). 55 patients with progression or new findings on the second cCT had no clinical signs of neurological deterioration. Of those 24 patients (44%) had therapeutic consequences due to the results of the follow-up cCT. Conclusion. We found new diagnosis or progression of intracranial pathology in 54% of the patients. In 54% of patients with new findings and progression of pathology, therapy was changed due to the results of follow-up cCT. In trauma patients who are sedated and ventilated for different reasons a routine follow-up CT is beneficial. KW - Computertomographie Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120084 IS - 361949 ER - TY - JOUR A1 - Schuster, Frank A1 - Johannsen, Stephan A1 - Moegele, Susanne A1 - Metterlein, Thomas A1 - Roewer, Norbert A1 - Anetseder, Martin T1 - The effect of succinylcholine on malignant hyperthermia events in susceptible swine N2 - Background While the impact of volatile anaesthetics to induce malignant hyperthermia (MH) is abundantly clear, the role of succinylcholine still remains controversial. To evaluate the influence of succinylcholine on porcine MH events, the authors investigated the hemodynamic and metabolic responses in MH susceptible (MHS) and non-susceptible (MHN) swine following either succinylcholine or halothane application alone or a combination of both substances. Methods With approval of the local animal care committee 27 MHS and 30 MHN pigs were anaesthetized and mechanically ventilated. Fiberoptic probes for continuous PCO2 measurement were inserted into the femoral vein and the triceps muscle. Group A received succinylcholine 4 mg/kg, group B incremental doses of halothane (0.5, 1.0 vol%) and group C succinylcholine and halothane simultaneously. Vital signs were recorded continuously. Results Prior to drug application measured values did not differ between MHS and MHN. While MHN pigs did not show relevant alterations, succinylcholine, halothane and the combination of both lead to significant hemodynamic and metabolic changes in MHS swine. Conclusions Hemodynamic and metabolic alterations following succinylcholine were similar to halothane in MHS pigs. The combination of both pharmacological agents potentiated the observed effects. According to these results succinylcholine acted as an independent and supportive factor during onset of an MH episode. KW - Malignant hyperthermia KW - Succinylcholine KW - Halothane KW - Swine Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110302 ER - TY - JOUR A1 - Rittner, Heike L. A1 - Sauer, Reine-Solange A1 - Hackel, Dagmar A1 - Morschel, Laura A1 - Sahlbach, Henrike A1 - Wang, Ying A1 - Mousa, Shaaban A. A1 - Roewer, Norbert A1 - Brack, Alexander T1 - Toll like receptor (TLR)-4 as a regulator of peripheral endogenous opioid-mediated analgesia in inflammation N2 - Background Leukocytes containing opioid peptides locally control inflammatory pain. In the early phase of complete Freund’s adjuvant (CFA)-induced hind paw inflammation, formyl peptides (derived e.g. from Mycobacterium butyricum) trigger the release of opioid peptides from neutrophils contributing to tonic basal antinociception. In the later phase we hypothesized that toll-like-receptor-(TLR)-4 activation of monocytes/macrophages triggers opioid peptide release and thereby stimulates peripheral opioid-dependent antinociception. Results In Wistar rats with CFA hind paw inflammation in the later inflammatory phase (48–96 h) systemic leukocyte depletion by cyclophosphamide (CTX) or locally injected naloxone (NLX) further decreased mechanical and thermal nociceptive thresholds. In vitro β-endorphin (β-END) content increased during human monocyte differentiation as well as in anti-inflammatory CD14+CD16- or non-classical M2 macrophages. Monocytes expressing TLR4 dose-dependently released β-END after stimulation with lipopolysaccharide (LPS) dependent on intracellular calcium. Despite TLR4 expression proinflammatory M1 and anti-inflammatory M2 macrophages only secreted opioid peptides in response to ionomycin, a calcium ionophore. Intraplantar injection of LPS as a TLR4 agonist into the inflamed paw elicited an immediate opioid- and dose-dependent antinociception, which was blocked by TAK-242, a small-molecule inhibitor of TLR4, or by peripheral applied NLX. In the later phase LPS lowered mechanical and thermal nociceptive thresholds. Furthermore, local peripheral TLR4 blockade worsened thermal and mechanical nociceptive pain thresholds in CFA inflammation. Conclusion Endogenous opioids from monocytes/macrophages mediate endogenous antinociception in the late phase of inflammation. Peripheral TLR4 stimulation acts as a transient counter-regulatory mechanism for inflammatory pain in vivo, and increases the release of opioid peptides from monocytes in vitro. TLR4 antagonists as new treatments for sepsis and neuropathic pain might unexpectedly transiently enhance pain by impairing peripheral opioid analgesia. KW - Toll like receptors KW - Analgesia KW - Inflammatory pain KW - Endogenous opioids Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110193 ER - TY - JOUR A1 - Müllenbach, Ralf Michael A1 - Roewer, Norbert A1 - Kranke, Peter T1 - Quality Assurance Would Be Welcome JF - Deutsches Ärzteblatt international N2 - No abstract available. KW - quality assurance KW - medicine Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128844 VL - 110 IS - 27-28 ER -