@article{JohannsenSchickRoeweretal.2018, author = {Johannsen, Stephan and Schick, Martin and Roewer, Norbert and Schuster, Frank}, title = {Microdialysis and ultrasound elastography for monitoring of localized muscular reaction after pharmacological stimulation in rats}, series = {BMC Research Notes}, volume = {11}, journal = {BMC Research Notes}, number = {636}, doi = {10.1186/s13104-018-3742-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176977}, year = {2018}, abstract = {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.}, language = {en} } @article{SchusterJohannsenIsbaryetal.2018, author = {Schuster, Frank and Johannsen, Stephan and Isbary, Susanne and T{\"u}rkmeneli, Ismail and Roewer, Norbert}, title = {In vitro effects of levosimendan on muscle of malignant hyperthermia susceptible and non-susceptible swine}, series = {BMC Anesthesiology}, volume = {18}, journal = {BMC Anesthesiology}, number = {182}, doi = {10.1186/s12871-018-0644-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176991}, year = {2018}, abstract = {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.}, language = {en} } @article{ChenLotzRoeweretal.2018, author = {Chen, Shasha and Lotz, Christopher and Roewer, Norbert and Broscheit, Jens-Albert}, title = {Comparison of volatile anesthetic-induced preconditioning in cardiac and cerebral system: molecular mechanisms and clinical aspects}, series = {European Journal of Medical Research}, volume = {23}, journal = {European Journal of Medical Research}, number = {10}, doi = {10.1186/s40001-018-0308-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175509}, year = {2018}, abstract = {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.}, language = {en} }