Diagnosis of Current Flow Patterns Inside Fault-Simulated Li-Ion Batteries via Non-Invasive, In Operando Magnetic Field Imaging.

With the growing popularity of Li-ion batteries in large-scale applications, building a safer battery has become a common goal of the battery community. Although the small errors inside the cells trigger catastrophic failures, tracing them and distinguishing cell failure modes without knowledge of cell anatomy can be challenging using conventional methods. In this study, a real-time, non-invasive magnetic field imaging (MFI) analysis that can signal the battery current-induced magnetic field and visualize the current flow within Li-ion cells is developed. A high-speed, spatially resolved MFI scan is used to derive the current distribution pattern from cells with different tab positions at a current load. Current maps are collected to determine possible cell failures using fault-simulated batteries that intentionally possess manufacturing faults such as lead-tab connection failures, electrode misalignment, and stacking faults (electrode folding). A modified MFI analysis exploiting the magnetic field interference with the countercurrent-carrying plate enables the direct identification of defect spots where abnormal current flow occurs within the pouch cells.

Sevoflurane in combination with esketamine is an effective sedation regimen in COVID-19 patients enabling assisted spontaneous breathing even during prone positioning.

BACKGROUND: Effective analgosedation for control of dyspnoea and for toleration of prone positioning (PP) in severe coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS) is difficult to adjust. This study was designed to evaluate the feasibility and safety of sedation with inhaled sevoflurane in combination with intravenous esketamine during PP in patients with COVID-19-ARDS (CARDS). METHODS: All mechanically ventilated COVID-19 patients admitted to the departmental intensive care unit from March to June 2020 were included in this epidemiological cohort study. Patients were sedated with inhaled sevoflurane in combination with eske-tamine during PP and not or only lightly sedated during the supine position. Assisted spontaneous breathing was applied in both prone and supine position. RESULTS: Adverse events were documented prospectively, and routine ventilation parameters, hemodynamic parameters, Richmond Agitation and Sedation Scale (RASS) and sevoflurane consumption were monitored. Altogether, 146 episodes of PP in 15 patients were observed. No severe sedation-related event was observed during 2610 hours of PP. In 2498 hours (96%) patients were successfully converted to a pressure-supported spontaneous breathing mode. CONCLUSIONS: Inhaled sedation with the AnaConDa-S-System (Sedana Medical AB, Danderyd, Sweden) alone is insufficient as soon as minute volume exceeds 7-8 L min-1, most likely due to technical reasons. Inhaled sedation with sevoflurane in combination with esketamine, however, safely enables prolonged prone positioning in patients with CARDS. Moreover, sedation depth was light enough to enable assisted spontaneous breathing during prone positioning.

Diagnosing capillary leak in critically ill patients: development of an innovative scoring instrument for non-invasive detection.

BACKGROUND: The concomitant occurrence of the symptoms intravascular hypovolemia, peripheral edema and hemodynamic instability is typically named Capillary Leak Syndrome (CLS) and often occurs in surgical critical ill patients. However, neither a unitary definition nor standardized diagnostic criteria exist so far. We aimed to investigate common characteristics of this phenomenon with a subsequent scoring system, determining whether CLS contributes to mortality. METHODS: We conducted this single-center, observational, multidisciplinary, prospective trial in two separately run surgical ICUs of a tertiary academic medical center. 200 surgical patients admitted to the ICU and 30 healthy volunteers were included. Patients were clinically diagnosed as CLS or No-CLS group (each N = 100) according to the grade of edema, intravascular hypovolemia, hemodynamic instability, and positive fluid balance by two independent attending physicians with > 10 years of experience in ICU. We performed daily measurements with non-invasive body impedance electrical analysis, ultrasound and analysis of serum biomarkers to generate objective diagnostic criteria. Receiver operating characteristics were used, while we developed machine learning models to increase diagnostic specifications for our scoring model. RESULTS: The 30-day mortility was increased among CLS patients (12 vs. 1%, P = 0.002), while showing higher SOFA-scores. Extracellular water was increased in patients with CLS with higher echogenicity of subcutaneous tissue [29(24-31) vs. 19(16-21), P < 0.001]. Biomarkers showed characteristic alterations, especially with an increased angiopoietin-2 concentration in CLS [9.9(6.2-17.3) vs. 3.7(2.6-5.6)ng/mL, P < 0.001]. We developed a score using seven parameters (echogenicity, SOFA-score, angiopoietin-2, syndecan-1, ICAM-1, lactate and interleukin-6). A Random Forest prediction model boosted its diagnostic characteristics (AUC 0.963, P < 0.001), while a two-parameter decision tree model showed good specifications (AUC 0.865). CONCLUSIONS: Diagnosis of CLS in critically ill patients is feasible by objective, non-invasive parameters using the CLS-Score. A simplified two-parameter diagnostic approach can enhance clinical utility. CLS contributes to mortality and should, therefore, classified as an independent entity. TRIAL REGISTRATION: German Clinical Trials Registry (DRKS No. 00012713), Date of registration 10/05/2017, www.drks.de.

Minimizing postoperative pulmonary complications in thoracic surgery patients.

PURPOSE OF REVIEW: Quantification and optimization of perioperative risk factors focusing on anesthesia-related strategies to reduce postoperative pulmonary complications (PPCs) after lung and esophageal surgery. RECENT FINDINGS: There is an increasing amount of multimorbid patients undergoing thoracic surgery due to the demographic development and medical progress in perioperative medicine. Nevertheless, the rate of PPCs after thoracic surgery is still up to 30-50% with a significant influence on patients' outcome. PPCs are ranked first among the leading causes of early mortality after thoracic surgery. Although patients' risk factors are usually barely modifiable, current research focuses on procedural risk factors. From the surgical position, the minimal-invasive approach using video-assisted thoracoscopy and laparoscopy leads to a decreased rate of PPCs. The anesthesiological strategy to reduce the incidence of PPCs after thoracic surgery includes neuroaxial anesthesia, lung-protective ventilation, and goal-directed hemodynamic therapy. SUMMARY: The main anesthesiological strategies to reduce PPCs after thoracic surgery include the use of epidural anesthesia, lung-protective ventilation: PEEP (positive end-expiratory pressure) of 5-8 mbar, tidal volume of 5 ml/kg BW (body weight) and goal-directed hemodynamics: CI (cardiac index) ≥ 2.5 l/min per m2, MAD (Mean arterial pressure) ≥ 70 mmHg, SVV (stroke volume variation) < 10% with a total amount of perioperative crystalloid fluids ≤ 6 ml/kg BW (body weight) per hour.

Subcutaneous Enoxaparin Safely Facilitates Bedside Sustained Low-Efficiency Hemodialysis in Hypercoagulopathic Coronavirus Disease 2019 Patients-A Proof-of-Principle Trial.

OBJECTIVES: Renal replacement therapy in coronavirus disease 2019 patients is complicated by increased activation of the coagulation system. This may worsen the quality of hemodialysis and contribute to a shortage of dialysis machines as well as plastic disposables during the pandemic. This study describes a simple and safe protocol of anticoagulation with low-molecular-weight heparin in combination with bedside sustained low-efficiency hemodialysis in coronavirus disease 2019 patients. DESIGN: Monocentric observational cross-over trial investigating sustained low-efficiency hemodialysis with unfractionated heparin following sustained low-efficiency hemodialysis with low-molecular-weight heparin. SETTING: Coronavirus disease 2019-ICU in a German Tertiary Care University Hospital. PATIENTS: Three consecutive severe coronavirus disease 2019 patients receiving nine sustained low-efficiency hemodialysis therapies with unfractionated heparin followed by 18 sustained low-efficiency hemodialysis therapies with low-molecular-weight heparin. INTERVENTIONS: Switch from IV unfractionated heparin to subcutaneous low-molecular-weight heparin enoxaparin in therapeutic doses for patients receiving bedside sustained low-efficiency hemodialysis. MEASUREMENTS AND MAIN RESULTS: Nine renal replacement therapy sessions in patients anticoagulated with high doses of unfractionated heparin had to be discontinuated prematurely because of clotting of tubes or membrane and poor quality of hemodialysis. In the same patients, the switch to anticoagulation with therapeutic doses of the low-molecular-weight heparin enoxaparin allowed undisturbed bedside sustained low-efficiency hemodialysis for at least 12 hours. Quality of hemodialysis was excellent, no bleeding event was observed. CONCLUSIONS: Systemic anticoagulation with subcutaneous enoxaparin provides an effective and safe renal replacement procedure in critically ill patients with coronavirus disease 2019 and hypercoagulability. The protocol reduces the risk of filter clotting, blood loss, and poor dialysis quality and may also prevent systemic thromboembolism.

Early Postoperative Use of Diuretics After Kidney Transplantation Showed Increase in Delayed Graft Function.

PURPOSE: In acute renal injury, diuretics are widely considered to be harmful. Nevertheless, they are used frequently after kidney transplantation. We hypothesized that diuretics administered in the early postoperative treatment after kidney transplantation increase the incidence of delayed graft function (DGF). METHODS: In this monocentric, retrospective cohort analysis, we screened the closed files of all consecutive patients who underwent kidney transplantation from 2011 to 2017. The outcome variable was DGF, defined as at least 1 hemodialysis within 7 days postoperatively. To stratify for baseline characteristics such as waiting time or cold ischemic period, we employed a propensity score-matched analysis. Further statistical processing included basic descriptive statistics, Mann-Whitney U test, and binary logistic regression analysis. RESULTS: The unmatched cohort included 445 patients and showed a significantly increased rate of DGF for patients who received either furosemide or mannitol or a combination of both (5% vs 25%; P < .001). Mannitol (odds ratio [OR]: 4.094) and furosemide (OR: 2.915) showed a significant correlation with DGF in the multivariate regression analysis. Propensity score-based matching resulted in a matched cohort of 214 patients with balanced baseline risk variables. In this matched cohort, the rate of DGF was significantly increased in patients who received diuretics in the early postoperative treatment (7% vs 16%; P = .031). CONCLUSION: Our results show that postoperatively administered diuretics are associated with an increased rate of DGF even in a cohort with balanced preoperative risk variables. This study supports recently published reviews, which call diuretics in the transplantation process into question.

Epidural analgesia and avoidance of blood transfusion are associated with reduced mortality in patients with postoperative pulmonary complications following thoracotomic esophagectomy: a retrospective cohort study of 335 patients.

BACKGROUND: Postoperative pulmonary complications (PPCs) represent the most frequent complications after esophagectomy. The aim of this study was to identify modifiable risk factors for PPCs and 90-days mortality related to PPCs after esophagectomy in esophageal cancer patients. METHODS: This is a single center retrospective cohort study of 335 patients suffering from esophageal cancer who underwent esophagectomy between 1996 and 2014 at a university hospital center. Statistical processing was conducted using univariate and multivariate stepwise logistic regression analysis of patient-specific and procedural risk factors for PPCs and mortality. RESULTS: The incidence of PPCs was 52% (175/335) and the 90-days mortality rate of patients with PPCs was 8% (26/335) in this study cohort. The univariate and multivariate analysis revealed the following independent risk factors for PPCs and its associated mortality. ASA score ≥ 3 was the only independent patient-specific risk factor for the incidence of PPCs and 90-days mortality of patients with an odds ratio for PPCs being 1.7 (1.1-2.6 95% CI) and an odds ratio of 2.6 (1.1-6.2 95% CI) for 90-days mortality. The multivariate approach depicted two independent procedural risk factors including transfusion of packed red blood cells (PRBCs) odds ratio of 1.9 (1.2-3 95% CI) for PPCs and an odds ratio of 5.0 (2.0-12.6 95% CI) for 90-days mortality; absence of thoracic epidural anesthesia (TEA) revealed the highest odds ratio 2.0 (1.01-3.8 95% CI) for PPCs and an odds ratio of 3.9 (1.6-9.7 95% CI) for 90-days mortality. CONCLUSION: In esophageal cancer patients undergoing esophagectomy via thoracotomy, epidural analgesia and the avoidance of intraoperative blood transfusion are significantly associated with a reduced 90-days mortality related to PPCs.

Modifiable Risk Factors for Delayed Graft Function After Deceased Donor Kidney Transplantation.

PURPOSE: Delayed graft function is a major complication after kidney transplantation affecting patients' long-term outcome. The aim of this study was to identify modifiable risk factors for delayed graft function after deceased donor kidney transplantation. METHODS: This is a single-center retrospective cohort study of a university transplantation center. Univariate and multivariate step-wise logistic regression analysis of patient-specific and procedural risk factors were conducted. RESULTS: We analyzed 380 deceased donor kidney transplantation patients between October 30, 2008 and December 30, 2017. The incidence of delayed graft function was 15% (58/380). Among the patient-specific risk factors recipient diabetes (2.8 [1.4-5.9] odds ratio [OR] [95% confidence interval [CI]]), American Society of Anesthesiologist score of 4 (2.7 [1.2-6.5] OR [95% CI]), cold ischemic time >13 hours (2.8 [1.5-5.3] OR [95% CI]) and donor age >55 years (1.9 [1.01-3.6] OR [95% CI]) revealed significance. The significant intraoperative, procedural risk factors included the use of colloids (3.9 [1.4-11.3] OR [95% CI]), albumin (3.0 [1.2-7.5] OR [95% CI]), crystalloids >3000 mL (3.1 [1.2-7.5] OR [95% CI]) and mean arterial pressure <80 mm Hg at the time of reperfusion (2.4 [1.2-4.8] OR [95% CI]). CONCLUSION: Patients undergoing deceased donor kidney transplantation with a mean arterial pressure >80 mm Hg at the time of transplant reperfusion without requiring excessive fluid therapy in terms of colloids, albumin or crystalloids >3000 mL are less likely to develop delayed graft function.

Risk factors for post-operative pulmonary complications in lung cancer patients after video-assisted thoracoscopic lung resection: Results of the German Thorax Registry.

OBJECTIVE: Post-operative pulmonary complications (PPCs) represent the most frequent complications after lung surgery. The aim of this study was to identify the modifiable risk factors for PPCs after video-assisted thoracoscopic surgery (VATS) in lung cancer patients. METHODS: Data of this retrospective study were extracted from the German Thorax Registry, an interdisciplinary and multicenter database of the German Society of Anesthesiology and Intensive care medicine and the German Society of Thoracic Surgery. Univariate and multivariate stepwise logistic regression analysis of patient-specific and procedural risk factors for PPCs were conducted. RESULTS: We analyzed 376 patients with lung cancer who underwent VATS bilobectomy (n = 2), lobectomy (n = 258) or segmentectomy (n = 116) in 2016 and 2017. One-hundred fourteen patients (114/376; 30%) developed PPCs. Two patients died within 30 days after surgery. In the univariate analysis, patients of the PPC group showed significantly more often a body mass index (BMI) ≤ 19 kg/m2 ; a pre-operative forced expiratory volume in 1 second (FEV1 ) ≤ 60%; a pre-operative arterial oxygen partial pressure (pa O2 ) ≤ 60 mm Hg; a higher rate of prolonged duration of surgery (≥2 hours [h]) and a higher frequency of intraoperative blood loss ≥500 mL. The multivariate stepwise logistic regression analysis revealed 4 independent risk factors: FEV1 ≤ 60% (1.9[1.1-3.4] OR [95% CI], P = 0.029); pa O2 ≤ 60 mm Hg (4.6[1.7-12.8] OR [95% CI], P = 0.003; duration of surgery ≥2 hours (2.7[1.5-4.7] OR [95% CI], P = 0.001) and intraoperative crystalloids ≥6 mL/kg/h (2.9[1.2-7.5] OR [95% CI], P = 0.023). CONCLUSION: Intraoperative amount of crystalloid fluids should be kept below 6 mL/kg/h and duration of surgery should be below 2 hours to avoid an increased risk for PPCs.

Lower rate of delayed graft function is observed when epidural analgesia for living donor nephrectomy is administered.

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 < 0.05, respectively. RESULTS: The study enclosed 291 consecutive living donor kidney transplantations. 99 kidney donors received epidural analgesia whereas 192 had no 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; none of these donors received EDA. The observed rate of DGF in recipients whose kidney donors received epidural analgesia was significantly lower (0% vs. 4.6%; p = 0.031). CONCLUSIONS: In our cohort we observed a significantly lower rate of DGF when epidural analgesia for donor nephrectomy was administered. Due to restrictions of the study design this observation needs further confirmation by prospective studies.

Does volatile sedation with sevoflurane allow spontaneous breathing during prolonged prone positioning in intubated ARDS patients? A retrospective observational feasibility trial.

BACKGROUND: Lung-protective ventilation and prolonged prone positioning (PP) are presented as essential in treating acute respiratory distress syndrome (ARDS). The optimal respirator mode, however, remains controversial. Pressure-supported spontaneous breathing (PS) during ARDS provides several advantages, but is difficult to achieve during PP because of respiratory depression as a side effect of sedative drugs. This study was designed to evaluate the feasibility and safety of PS during PP in ARDS patients sedated with inhaled sevoflurane. RESULTS: Overall, we have observed 4339 h of prone positioning in 62 patients who had a median of four prone episodes during treatment. Within 3948 h (91%), patients were successfully brought into a pressure-supported spontaneous breathing mode. The median duration of each prone episode was 17 h (IQR 3). Median duration of pressure-supported spontaneous breathing per episode was 16 h (IQR 5). Just one self-extubation occurred during 276 episodes of PP. CONCLUSIONS AND IMPLICATIONS: Pressure-supported spontaneous breathing during prolonged prone positioning in intubated ARDS patients with or without ECMO can be achieved during volatile sedation with sevoflurane. This finding may provide a basis upon which to question the latest dogma in ARDS treatment. Our concept must be further investigated and compared to controlled ventilation with regard to driving pressure, lung-protective parameters, muscle weakness and mortality before it can be routinely applied.

Electromagnetic Functionalization of Wide-Bandgap Dielectric Oxides by Boron Interstitial Doping.

A surge in interest of oxide-based materials is testimony for their potential utility in a wide array of device applications and offers a fascinating landscape for tuning the functional properties through a variety of physical and chemical parameters. In particular, selective electronic/defect doping has been demonstrated to be vital in tailoring novel functionalities, not existing in the bulk host oxides. Here, an extraordinary interstitial doping effect is demonstrated centered around a light element, boron (B). The host matrix is a novel composite system, made from discrete bulk LaAlO3 :LaBO3 compounds. The findings show a spontaneous ordering of the interstitial B cations within the host LaAlO3 lattices, and subsequent spin-polarized charge injection into the neighboring cations. This leads to a series of remarkable cation-dominated electrical switching and high-temperature ferromagnetism. Hence, the induced interstitial doping serves to transform a nonmagnetic insulating bulk oxide into a ferromagnetic ionic-electronic conductor. This unique interstitial B doping effect upon its control is proposed to be as a general route for extracting/modifying multifunctional properties in bulk oxides utilized in energy and spin-based applications.

Perioperative cytokine profile during lung surgery predicts patients at risk for postoperative complications-A prospective, clinical study.

BACKGROUND: Postoperative complications after lung surgery are frequent, having a detrimental effect on patients' further course. Complications may lead to an increased length of hospital stay and cause additional costs. Several risk factors have been identified but it is still difficult to predict contemporary which patients are at risk. We hypothesized that patients who show an increased inflammatory response at the time of wound closure and 24 hours after surgery are at risk of postoperative complications within 30 days after surgery. METHODS: Postoperative complications (pulmonary, cardiac, neurological and renal) of 96 patients scheduled for lung surgery at the Medical Center-University of Freiburg were analyzed in this prospective, clinical study. Blood samples for cytokine analysis (Interleukin (IL)-6, IL-8, IL-10, Tumor necrosis factor [TNF]-α, IL-1ß and IL12p70) were taken before surgery, at wound closure and 24 hours after surgery. Cytokine levels of patients with and without postoperative complications were analyzed by Receiver operating characteristic (ROC) curve analysis. To adjust the results according to existing covariates a multivariate logistic regression analysis was conducted. RESULTS: The complication and non-complication group differed significantly according to nicotine dependency, Angiotensin-receptor-II blocker medication, rate of thoracotomy and preoperative lung function. The intraoperative hemodynamic parameters and therapy did not differ between the groups. Twenty-nine patients (30%) developed postoperative complications within 30 days after surgery. Plasma concentrations of IL-6, IL-10 and IL-8 at the time of wound closure and 24 hours after surgery were higher in the complication group. Multivariate regression analysis on postoperative complications revealed an Odds ratio of 56 for patients with IL-6 and IL-8 levels above the 3rd quartile measured on the first postoperative day. CONCLUSIONS: Perioperative detection of increased plasma concentrations of inflammatory cytokines in lung surgery may be used in addition to other clinical predictors to identify patients at risk for postoperative complications. TRIAL REGISTRATION: German Clinical Trials Register 00006961.

Evaluation of hemodynamic goal-directed therapy to reduce the incidence of bone cement implantation syndrome in patients undergoing cemented hip arthroplasty - a randomized parallel-arm trial.

BACKGROUND: The bone cement implantation syndrome (BCIS) is a frequent and potentially disastrous intraoperative complication in patients undergoing cemented hip arthroplasty. Several risk factors have been identified, however randomized controlled trials to reduce the incidence of BCIS are still pending. We hypothesized that goal-directed hemodynamic therapy guided by esophageal Doppler monitoring (EDM) may reduce the incidence of BCIS in a randomized, controlled parallel-arm trial. METHODS: After approval of the local ethics committee, 90 patients scheduled for cemented hip arthroplasty at the Medical Center - University of Freiburg were randomly assigned to either standard hemodynamic management or goal-directed therapy (GDT) guided by an esophageal Doppler monitoring-based algorithm. The primary endpoint was the incidence of overall BCIS including grade 1-3 after cementation of the femoral stem. Secondary endpoints included cardiac function, length of hospital stay and postoperative complications. RESULTS: Ninety patients were finally analyzed. With regards to the primary endpoint, the overall incidence of BCIS showed no difference between the GDT and control group. Compared to the control group, patients of the GDT group showed a higher cardiac index before and after bone cement implantation (2.7 vs. 2.2 [l●min- 1●m- 2]; 2.8 vs. 2.4 [l●min- 1●m- 2]; P = 0.003, P = 0.042), whereas intraoperative amount of fluids and mean arterial pressure did not differ. CONCLUSIONS: The implementation of a specific hemodynamic goal-directed therapy did not reduce the overall incidence of BCIS in patients undergoing cemented hip arthroplasty. TRIAL REGISTRATION: This randomized clinical two-arm parallel study was approved by the local Ethics Committee, Freiburg, Germany [EK 160/15, PI: U. Goebel] and registered in the German Clinical Trials Register ( DRKS No. 00008778 , 16th of June, 2015).

The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells.

PURPOSE: Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. METHODS: IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. RESULTS: ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. CONCLUSION: In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI.

Argon mediates protection by interleukin-8 suppression via a TLR2/TLR4/STAT3/NF-κB pathway in a model of apoptosis in neuroblastoma cells in vitro and following ischemia-reperfusion injury in rat retina in vivo.

Argon has recently come into scientific focus as a neuroprotective agent. The underlying neuroprotective mechanism remains unknown although toll-like receptors were recently suggested to play an important role. We hypothesized that TLR-associated downstream transcription factors are responsible for argon's effects, leading to anti-apoptotic and anti-inflammatory properties. Apoptosis was induced in human neuroblastoma cells. Immediately afterwards, argon treatment (75 Vol% for 2 h) was initiated. Cells were analyzed, measuring mitochondrial membrane potential, reactive-oxygen-species, annexin-V/propidium iodide staining, transcription factor phosphorylation and binding activity as well as protein and mRNA expression of interleukins. Argon's in vivo effects were analyzed by quantification of retinal ganglion cell density, mRNA expression, serum cytokine analysis and immunohistochemistry after retinal ischemia reperfusion injury (IRI) in rats. Argon diminished rotenone-induced kappa-light-chain-enhancer' of activated B-cells (NF-κB) and signal transducer and activator of transcription 3 (STAT3) but not STAT5 or cAMP-response element-binding protein (CREB) phosphorylation and DNA-binding activity. Argon treatment attenuated apoptosis by preservation of mitochondrial membrane potential and decline in reactive oxygen species (ROS) generation. NF-κB and STAT3 inhibition, as well as TLR2 and TLR4 inhibition reversed argon's effects on IL-8 mRNA expression. Argon attenuated rotenone-induced IL-8 protein and mRNA expression in vitro. Inhibition of TLR2 and 4 attenuated argon's protective effect in vivo reducing IRI driven retinal IL-8 expression. IL-8 expression was found in the retina in co-localization with Müller cells and retinal ganglion cells. Argon mediates its neuroprotective effects by TLR-mediated regulation of transcription factors NF-κB and STAT3, thus decreasing interleukin-8 expression in vitro and in vivo. These findings may open up new opportunities to effectively treat cerebral ischemia and reperfusion injury through the inhalation of argon. Argon exerts its protective effects in vitro and in vivo via toll-like receptors TLR2 and TLR4 signaling, followed by alteration of downstream enzymes. In conclusion, argon mediates its beneficial effects by suppression of STAT3 and NF-κB phosphorylation and subsequent suppression of interleukin IL-8 protein expression. These novel findings may open up opportunities for argon as a therapeutic agent, particularly in the treatment of neuronal injury. Cover image for this issue: doi: 10.1111/jnc.13334.

The anti-inflammatory effects of E-α-(p-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone are mediated via HO-1 induction.

Inflammation plays a central role in the pathophysiology of many diseases. The inducible enzyme heme oxygenase-1 (HO-1) protects cells against inflammation and can be induced by electrophilic compounds like the chalcones (1,3-diphenylprop-2-enones) from the class of α,ß-unsaturated carbonyl compounds. We hypothesized that the synthetic chalcone E-α-(p-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC) exerts anti-inflammatory effects in RAW264.7, Jurkat lymphocytes and HK-2 cells via HO-1 induction. RAW264.7 cells were treated with lipopolysaccharide prior to E-α-p-OMe-C6H4-TMC treatment. Subsequently, HO-1 protein induction and activity were analyzed, as well as expression of pro- and anti-inflammatory mediators, transcription factors and mitogen-activated protein kinases to evaluate the possible molecular mechanism. These results were confirmed in human cell lines (Jurkat T-lymphocytes and HK-2 epithelial cells). We found that the E-α-p-OMe-C6H4-TMC exerts significant anti-inflammatory effects in a dose dependent manner, showing no toxic effects in LPS-treated RAW264.7 macrophages. E-α-p-OMe-C6H4-TMC induced HO-1 and SOD-1 protein expression and HO-1 enzyme activity, reduced the upregulation of COX-2 and iNOS, while inducing the translocation of Nrf2. NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment accompanied by the downregulation of proinflammatory cytokines IL-1ß, IL-6 and MCP-1. Pretreatment with E-α-p-OMe-C6H4-TMC revealed significant changes in phosphorylation of ERK and p38, but not JNK. These anti-inflammatory effects of E-α-p-OMe-C6H4-TMC were approved in Jurkat and HK-2 cells, furthermore revealing a downregulation of IL-8 and IL-10. In conclusion, it is tempting to speculate about E-α-p-OMe-C6H4-TMC as a new and non-toxic agent, inducing HO-1 in cells. This opens up new opportunities regarding the development of therapeutic agents using beneficial effects of HO-1 and its products.

Argon Mediates Anti-Apoptotic Signaling and Neuroprotection via Inhibition of Toll-Like Receptor 2 and 4.

PURPOSE: Recently, the noble gas argon attracted significant attention due to its neuroprotective properties. However, the underlying molecular mechanism is still poorly understood. There is growing evidence that the extracellular regulated kinase 1/2 (ERK1/2) is involved in Argon´s protective effect. We hypothesized that argon mediates its protective effects via the upstream located toll-like receptors (TLRs) 2 and 4. METHODS: Apoptosis in a human neuroblastoma cell line (SH-SY5Y) was induced using rotenone. Argon treatment was performed after induction of apoptosis with different concentrations (25, 50 and 75 Vol% in oxygen 21 Vol%, carbon dioxide and nitrogen) for 2 or 4 hours respectively. Apoptosis was analyzed using flow cytometry (annexin-V (AV)/propidiumiodide (PI)) staining, caspase-3 activity and caspase cleavage. TLR density on the cells' surface was analyzed using FACS and immunohistochemistry. Inhibition of TLR signaling and extracellular regulated kinase 1/2 (ERK1/2) were assessed by western blot, activity assays and FACS analysis. RESULTS: Argon 75 Vol% treatment abolished rotenone-induced apoptosis. This effect was attenuated dose- and time-dependently. Argon treatment was accompanied with a significant reduction of TLR2 and TLR4 receptor density and protein expression. Moreover, argon mediated increase in ERK1/2 phosphorylation was attenuated after inhibition of TLR signaling. ERK1/2 and TLR signaling inhibitors abolished the anti-apoptotic and cytoprotective effects of argon. Immunohistochemistry results strengthened these findings. CONCLUSION: These findings suggest that argon-mediated anti-apoptotic and neuroprotective effects are mediated via inhibition of TLR2 and TLR4.

The Cytoprotective Effects of E-α-(4-Methoxyphenyl)-2',3,4,4'-Tetramethoxychalcone (E-α-p-OMe-C6H4-TMC)--A Novel and Non-Cytotoxic HO-1 Inducer.

Cell protection against different noxious stimuli like oxidative stress or chemical toxins plays a central role in the treatment of many diseases. The inducible heme oxygenase isoform, heme oxygenase-1 (HO-1), is known to protect cells against a variety of harmful conditions including apoptosis. Because a number of medium strong electrophiles from a series of α-X-substituted 2',3,4,4'-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, CN, Me, p-NO2-C6H4, Ph, p-OMe-C6H4, NO2, CF3, COOEt, COOH) had proven to activate Nrf2 resulting in HO-1 induction and inhibit NF-κB downstream target genes, their protective effect against staurosporine induced apoptosis and reactive oxygen species (ROS) production was investigated. RAW264.7 macrophages treated with 19 different chalcones (15 α-X-TMCs, chalcone, 2'-hydroxychalcone, calythropsin and 2'-hydroxy-3,4,4'-trimethoxychalcone) prior to staurosporine treatment were analyzed for apoptosis and ROS production, as well as HO-1 protein expression and enzyme activity. Additionally, Nrf2 and NF-κB activity was assessed. We found that amongst all tested chalcones only E-α-(4-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC) demonstrated a distinct, statistically significant antiapoptotic effect in a dose dependent manner, showing no toxic effects, while its double bond isomer Z-α-p-OMe-C6H4-TMC displayed no significant activity. Also, E-α-p-OMe-C6H4-TMC induced HO-1 protein expression and increased HO-1 activity, whilst inhibition of HO-1 by SnPP-IX abolished its antiapoptotic effect. The only weakly electrophilic chalcone E-α-p-OMe-C6H4-TMC reduced the staurosporine triggered formation of ROS, while inducing the translocation of Nrf2 into the nucleus. Furthermore, staurosporine induced NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment. Overall, E-α-p-OMe-C6H4-TMC demonstrated its effective cytoprotective potential via a non-toxic induction of HO-1 in RAW264.7 macrophages. The observed cytoprotective effect may partly be related to both, the activation of the Nrf2- and inhibition of the NF-κB pathway.

Neuroprotective effects of Argon are mediated via an ERK-1/2 dependent regulation of heme-oxygenase-1 in retinal ganglion cells.

Retinal ischemia and reperfusion injuries (R-IRI) damage neuronal tissue permanently. Recently, we demonstrated that Argon exerts anti-apoptotic and protective properties. The molecular mechanism remains unclear. We hypothesized that Argon inhalation exert neuroprotective effects in rats retinal ganglion cells (RGC) via an ERK-1/2 dependent regulation of heat-shock proteins. Inhalation of Argon (75 Vol%) was performed after R-IRI on the rats' left eyes for 1 h immediately or with delay. Retinal tissue was harvested after 24 h to analyze mRNA and protein expression of heat-shock proteins -70, -90 and heme-oxygenase-1, mitogen-activated protein kinases (p38, JNK, ERK-1/2) and histological changes. To analyze ERK dependent effects, the ERK inhibitor PD98059 was applicated prior to Argon inhalation. RGC count was analyzed 7 days after injury. Statistics were performed using anova. Argon significantly reduced the R-IRI-affected heat-shock protein expression (p < 0.05). While Argon significantly induced ERK-1/2 expression (p < 0.001), inhibition of ERK-1/2 before Argon inhalation resulted in significantly lower vital RGCs (p < 0.01) and increase in heme-oxygenase-1 (p < 0.05). R-IRI-induced RGC loss was reduced by Argon inhalation (p < 0.001). Immunohistochemistry suggested ERK-1/2 activation in Müller cells. We conclude, that Argon treatment protects R-IRI-induced apoptotic loss of RGC via an ERK-1/2 dependent regulation of heme-oxygenase-1. We proposed the following possible mechanism for Argon-mediated neuroprotection: Argon exerts its protective effects via an induction of an ERK with subsequent suppression of the heat shock response. In conclusion, ischemia and reperfusion injuries and subsequent neuronal apoptosis are attenuated. These novel findings may open up new opportunities for Argon as a therapeutic option, especially since Argon is not toxic.