@article{SchusterJohannsenSchneiderbangeretal.2013, author = {Schuster, Frank and Johannsen, Stephan and Schneiderbanger, Daniel and Roewer, Norbert}, title = {Evaluation of suspected malignant hyperthermia events during anesthesia}, series = {BMC Anesthesiology}, journal = {BMC Anesthesiology}, doi = {10.1186/1471-2253-13-24}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96231}, year = {2013}, abstract = {Background Malignant hyperthermia (MH), a metabolic myopathy triggered by volatile anesthetics and depolarizing muscle relaxants, is a potentially lethal complication of general anesthesia in susceptible patients. The implementation of modern inhalation anesthetics that research indicates as less potent trigger substances and the recommended limitations of succinylcholine use, suggests there may be considerable decline of fulminant MH cases. In the presented study, the authors analyzed suspected MH episodes during general anesthesia of patients that were referred to the Wuerzburg MH unit between 2007 and 2011, assuming that MH is still a relevant anesthetic problem in our days. Methods With approval of the local ethics committee data of patients that underwent muscle biopsy and in vitro contracture test (IVCT) between 2007 and 2011 were analyzed. Only patients with a history of suspected MH crisis were included in the study. The incidents were evaluated retrospectively using anesthetic documentation and medical records. Results Between 2007 and 2011 a total of 124 patients were tested. 19 of them were referred because of suspected MH events; 7 patients were diagnosed MH-susceptible, 4 MH-equivocal and 8 MH-non-susceptible by IVCT. In a majority of cases masseter spasm after succinylcholine had been the primary symptom. Cardiac arrhythmias and hypercapnia frequently occurred early in the course of events. Interestingly, dantrolene treatment was initiated in a few cases only. Conclusions MH is still an important anesthetic complication. Every anesthetist must be aware of this life-threatening syndrome at any time. The rapid onset of adequate therapy is crucial to avoid major harm and possibly lethal outcome. Dantrolene must be readily available wherever MH triggering agents are used for anesthesia.}, language = {en} } @article{ShityakovSohajdaPuskasetal.2014, author = {Shityakov, Sergey and Sohajda, Tam{\´a}s and Puskas, Istav{\´a}n and Roewer, Norbert and F{\"o}rster, Carola and Broscheit, Jens-Albert}, title = {Ionization States, Cellular Toxicity and Molecular Modeling Studies of Midazolam Complexed with Trimethyl-β-Cyclodextrin}, series = {Molecules}, volume = {19}, journal = {Molecules}, number = {10}, doi = {10.3390/molecules191016861}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119186}, pages = {16861-76}, year = {2014}, abstract = {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.}, language = {en} } @article{SchickBaarFlemmingetal.2014, author = {Schick, Martin A. and Baar, Wolfgang and Flemming, Sven and Schlegel, Nicolas and Wollborn, Jakob and Held, Christopher and Schneider, Reinhard and Brock, Robert W. and Roewer, Norbert and Wunder, Christian}, title = {Sepsis-induced acute kidney injury by standardized colon ascendens stent peritonitis in rats - a simple, reproducible animal model}, series = {Intensive Care Medicine Experimental}, volume = {2}, journal = {Intensive Care Medicine Experimental}, number = {34}, doi = {10.1186/s40635-014-0034-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126111}, year = {2014}, abstract = {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.}, language = {en} } @article{ShityakovPuskasRoeweretal.2014, author = {Shityakov, Sergey and Pusk{\´a}s, Istv{\´a}n and Roewer, Norbert and F{\"o}rster, Carola and Broscheit, Jens}, title = {Three-dimensional quantitative structure-activity relationship and docking studies in a series of anthocyanin derivatives as cytochrome P450 3A4 inhibitors}, series = {Advances and Applications in Bioinformatics and Chemistry}, volume = {7}, journal = {Advances and Applications in Bioinformatics and Chemistry}, doi = {10.2147/AABC.S56478}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120226}, pages = {11-21}, year = {2014}, abstract = {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.}, language = {en} } @article{WurmbSchlerethKredeletal.2014, author = {Wurmb, Thomas Erik and Schlereth, Stefan and Kredel, Markus and Muellenbach, Ralf M. and Wunder, Christian and Brederlau, J{\"o}rg and Roewer, Norbert and Kenn, Werner and Kunze, Ekkehard}, title = {Routine Follow-Up Cranial Computed Tomography for Deeply Sedated, Intubated, and Ventilated Multiple Trauma Patients with Suspected Severe Head Injury}, series = {BioMed Research International}, journal = {BioMed Research International}, number = {361949}, doi = {10.1155/2014/361949}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120084}, year = {2014}, abstract = {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.}, language = {en} } @article{SchusterJohannsenMoegeleetal.2014, author = {Schuster, Frank and Johannsen, Stephan and Moegele, Susanne and Metterlein, Thomas and Roewer, Norbert and Anetseder, Martin}, title = {The effect of succinylcholine on malignant hyperthermia events in susceptible swine}, doi = {10.1186/1471-2253-14-14}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110302}, year = {2014}, abstract = {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.}, language = {en} } @article{RittnerSauerHackeletal.2014, author = {Rittner, Heike L. and Sauer, Reine-Solange and Hackel, Dagmar and Morschel, Laura and Sahlbach, Henrike and Wang, Ying and Mousa, Shaaban A. and Roewer, Norbert and Brack, Alexander}, title = {Toll like receptor (TLR)-4 as a regulator of peripheral endogenous opioid-mediated analgesia in inflammation}, doi = {10.1186/1744-8069-10-10}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110193}, year = {2014}, abstract = {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.}, language = {en} } @article{SchickBaarBrunoetal.2015, author = {Schick, Martin Alexander and Baar, Wolfgang and Bruno, Raphael Romano and Wollborn, Jakob and Held, Christopher and Schneider, Reinhard and Flemming, Sven and Schlegel, Nicolas and Roewer, Norbert and Neuhaus, Winfried and Wunder, Christian}, title = {Balanced hydroxyethylstarch (HES 130/0.4) impairs kidney function in-vivo without inflammation}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {9}, doi = {10.1371/journal.pone.0137247}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126068}, pages = {e0137247}, year = {2015}, abstract = {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}, language = {en} } @article{WurmbVollmerSefrinetal.2015, author = {Wurmb, Thomas and Vollmer, Tina and Sefrin, Peter and Kraus, Martin and Happel, Oliver and Wunder, Christian and Steinisch, Andrias and Roewer, Norbert and Maier, Sebastian}, title = {Monitoring of in-hospital cardiac arrest events with the focus on Automated External Defibrillators - a retrospective observational study}, series = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, volume = {23}, journal = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, number = {87}, doi = {10.1186/s13049-015-0170-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125756}, year = {2015}, abstract = {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.}, language = {en} } @article{ShityakovPuskasPapaietal.2015, author = {Shityakov, Sergey and Pusk{\´a}s, Istv{\´a}n and P{\´a}pai, Katalin and Salvador, Ellaine and Roewer, Norbert and F{\"o}rster, Carola and Broscheit, Jens-Albert}, title = {Sevoflurane-sulfobutylether-\(\beta\)-cyclodextrin complex: preparation, characterization, cellular toxicity, molecular modeling and blood-brain barrier transport studies}, series = {Molecules}, volume = {20}, journal = {Molecules}, doi = {10.3390/molecules200610264}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148543}, pages = {10264-10279}, year = {2015}, abstract = {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.}, language = {en} }