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Background: Perioperative damage of neuronal tissue due to insufficient cerebral circulation as a result of hypotension or stroke, lead to permanent destruction and functional impairment via apoptotic and inflammatory pathways. Recently, the noble gas argon has been shown to exert neuroprotective effects. Despite intensive research, the exact mechanism remains unclear. Methods: In-vitro, after injury of human neuroblastoma cells with rotenone over a period of four hours, postconditioning with argon 75 Vol% was performed for 2. In-vivo, retinal ischemia reperfusion injury in the rat was induced by increasing intraocular pressure for 1 hour (h). Upon reperfusion, argon was administered by inhalation for 2 h. Results: In summary, argon reduced binding activity of transcription factors involved in regulation of neuronal damage such as STAT3 (Signal transducer and activator of transcription 3), NF-kB (Nuclear factor `kappa-light-chain-enhancer´ of activated B-cells), AP-1 (Activator protein 1) and Nrf-2 (Nuclear factor erythroid 2-related factor 2). Flow cytometry analysis showed that argon down-regulated the Fas-Ligand. Since some of these transcription factors were regulated via toll-like receptors (TLR), their effects could be eliminated - at least in part - by OxPAPC (TLR2 and -4 inhibitor). Argon was able to reduce the quantity and the activity of neuronal microglia after ischemia-reperfusion injury. Consecutively, qPCR (quantitative Polymerase chain reaction) showed a reduction of the pro-inflammatory cytokines IL-1α (Interleukin-1α), IL-1ß (Interleukin-1ß), IL-6 (Interleukin 6), TNFα (Tumor necrosis factor alpha) and iNOS (inducible Nitric oxide synthase). Conclusion: Argon reduced the extent of inflammation after neuronal injury by suppression of transcription factors crucial for microglia activation. The therapeutic use of the noble gas would be ideal for treating in the context of neuronal damage due to the lack of known side effects and narcotic properties with preservation of neurological assessability. Although preclinical studies are promising, further investigations are required before argon can be approved for use in patients.

Background The beneficial effects of epidural analgesia (EDA) in terms of pain control and postoperative convalescence are widely known and led to a frequent use for patients who underwent living donor kidney nephrectomy. The objective of this study was to determine whether general anesthesia (GA) plus EDA compared to GA only, administered for living donor nephrectomy has effects on postoperative graft function in recipients. Methods In this monocentric, retrospective cohort analysis we analyzed the closed files of all consecutive donor- recipient pairs who underwent living donor kidney transplantations from 2008 to 2017. The outcome variable was delayed graft function (DGF), defined as at least one hemodialysis within seven days postoperatively, once hyperacute rejection, vascular or urinary tract complications were ruled out. Statistical analyses of continuous variables were calculated using the two-tail Student’s t test and Fisher exact test for categorical variables with a significance level of p

Background: The beneficial effects of epidural analgesia (EDA) in terms of pain control and postoperative convalescence are widely known and led to a frequent use for patients who underwent living donor kidney nephrectomy. The objective of this study was to determine whether general anesthesia (GA) plus EDA compared to GA only, administered for living donor nephrectomy has effects on postoperative graft function in recipients. Methods: In this monocentric, retrospective cohort analysis we analyzed the closed files of all consecutive donor- recipient pairs who underwent living donor kidney transplantations from 2008 to 2017. The outcome variable was delayed graft function (DGF), defined as at least one hemodialysis within seven days postoperatively, once hyperacute rejection, vascular or urinary tract complications were ruled out. Statistical analyses of continuous variables were calculated using the two-tail Student’s t test and Fisher exact test for categorical variables with a significance level of pResults: The study enclosed 291 consecutive living donor kidney transplantations. 99 kidney donors received epidural analgesia whereas 192 denied epidural analgesia. The groups showed balanced pretransplantational characteristics and comparable donors´ and recipients’ risk factors. 9 out of all 291 recipients needed renal replacement therapy (RRT) during the first 7 days due to delayed graft function; all of these donors received no EDA. The observed rate of DGF in recipients whose kidney donors received epidural analgesia was significantly lower (0% vs. 4.6%; pConclusions: In our cohort we observed a significantly lower rate of DGF when epidural analgesia for donor nephrectomy was administered. Du to restrictions of the study design this observation needs further confirmation by prospective studies. Key words: Kidney transplantation, delayed graft function, epidural analgesia, donor nephrectomy