Klinik und Poliklinik für Anästhesiologie (ab 2004)
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Schlagworte
- COVID-19 (12)
- blood-brain barrier (11)
- inflammation (10)
- endothelial cells (8)
- molecular docking (8)
- blood–brain barrier (7)
- cytokines (6)
- sepsis (6)
- microRNA (5)
- stroke (5)
Institut
- Klinik und Poliklinik für Anästhesiologie (ab 2004) (183)
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) (14)
- Medizinische Klinik und Poliklinik I (11)
- Neurochirurgische Klinik und Poliklinik (11)
- Theodor-Boveri-Institut für Biowissenschaften (9)
- Frauenklinik und Poliklinik (7)
- Institut für Anatomie und Zellbiologie (6)
- Kinderklinik und Poliklinik (6)
- Institut für Klinische Epidemiologie und Biometrie (5)
- Institut für Klinische Neurobiologie (5)
Sonstige beteiligte Institutionen
- Zentrallabor, Universitätsklinikum Würzburg (2)
- Apotheke, Universitätsklinikum Würzburg (1)
- Department of Medicinal Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria (1)
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria (1)
- EMBL Mouse Biology Unit, Monterotondo, Italien (1)
- Interdisziplinäres Zentrum für Klinische Forschung (ZIKF), Würzburg (1)
- Klinik und Poliklinik für Anästhesiologie, Intensivmedizin, Notfallmedizin und Schmerztherapie des Universitätsklinikums Würzburg (1)
- Krankenhaushygiene und Antimicrobial Stewardship (1)
- Krankenhaushygiene und Antimicrobial Stewardship, Universitätsklinikum Würzburg (1)
Background and objectives
Preoperative anaemia is an independent risk factor for a higher morbidity and mortality, a longer hospitalization and increased perioperative transfusion rates. Managing preoperative anaemia is the first of three pillars of Patient Blood Management (PBM), a multidisciplinary concept to improve patient safety. While various studies provide medical information on (successful) anaemia treatment pathways, knowledge of organizational details of diagnosis and management of preoperative anaemia across Europe is scarce.
Materials and methods
To gain information on various aspects of preoperative anaemia management including organization, financing, diagnostics and treatment, we conducted a survey (74 questions) in ten hospitals from seven European nations within the PaBloE (Patient Blood Management in Europe) working group covering the year 2016.
Results
Organization and activity in the field of preoperative anaemia management were heterogeneous in the participating hospitals. Almost all hospitals had pathways for managing preoperative anaemia in place, however, only two nations had national guidelines. In six of the ten participating hospitals, preoperative anaemia management was organized by anaesthetists. Diagnostics and treatment focused on iron deficiency anaemia which, in most hospitals, was corrected with intravenous iron.
Conclusion
Implementation and approaches of preoperative anaemia management vary across Europe with a primary focus on treating iron deficiency anaemia. Findings of this survey motivated the hospitals involved to critically evaluate their practice and may also help other hospitals interested in PBM to develop action plans for diagnosis and management of preoperative anaemia.
Health economics of Patient Blood Management: a cost‐benefit analysis based on a meta‐analysis
(2020)
Background and Objectives
Patient Blood Management (PBM) is the timely application of evidence‐based medical and surgical concepts designed to improve haemoglobin concentration, optimize haemostasis and minimize blood loss in an effort to improve patient outcomes. The focus of this cost‐benefit analysis is to analyse the economic benefit of widespread implementation of a multimodal PBM programme.
Materials and Methods
Based on a recent meta‐analysis including 17 studies (>235 000 patients) comparing PBM with control care and data from the University Hospital Frankfurt, a cost‐benefit analysis was performed. Outcome data were red blood cell (RBC) transfusion rate, number of transfused RBC units, and length of hospital stay (LOS). Costs were considered for the following three PBM interventions as examples: anaemia management including therapy of iron deficiency, use of cell salvage and tranexamic acid. For sensitivity analysis, a Monte Carlo simulation was performed.
Results
Iron supplementation was applied in 3·1%, cell salvage in 65% and tranexamic acid in 89% of the PBM patients. In total, applying these three PBM interventions costs €129·04 per patient. However, PBM was associated with a reduction in transfusion rate, transfused RBC units per patient, and LOS which yielded to mean savings of €150·64 per patient. Thus, the overall benefit of PBM implementation was €21·60 per patient. In the Monte Carlo simulation, the cost savings on the outcome side exceeded the PBM costs in approximately 2/3 of all repetitions and the total benefit was €1 878 000 in 100·000 simulated patients.
Conclusion
Resources to implement a multimodal PBM concept optimizing patient care and safety can be cost‐effectively.
Background
Processing and analysis of DNA sequences obtained from next-generation sequencing (NGS) face some difficulties in terms of the correct prediction of DNA sequencing outcomes without the implementation of bioinformatics approaches. However, algorithms based on NGS perform inefficiently due to the generation of long DNA fragments, the difficulty of assembling them and the complexity of the used genomes. On the other hand, the Sanger DNA sequencing method is still considered to be the most reliable; it is a reliable choice for virtual modeling to build all possible consensus sequences from smaller DNA fragments.
Results
In silico and in vitro experiments were conducted: (1) to implement and test our novel sequencing algorithm, using the standard cloning vectors of different length and (2) to validate experimentally virtual shotgun sequencing using the PCR technique with the number of cycles from 1 to 9 for each reaction.
Conclusions
We applied a novel algorithm based on Sanger methodology to correctly predict and emphasize the performance of DNA sequencing techniques as well as in de novo DNA sequencing and its further application in synthetic biology. We demonstrate the statistical significance of our results.
Within the lipidome oxidized phospholipids (OxPL) form a class of chemically highly reactive metabolites. OxPL are acutely produced in inflamed tissue and act as endogenous, proalgesic (pain-inducing) metabolites. They excite sensory, nociceptive neurons by activating transient receptor potential ion channels, specifically TRPA1 and TRPV1. Under inflammatory conditions, OxPL-mediated receptor potentials even potentiate the action potential firing rate of nociceptors. Targeting OxPL with D-4F, an apolipoprotein A-I mimetic peptide or antibodies like E06, specifically binding oxidized headgroups of phospholipids, can be used to control acute, inflammatory pain syndromes, at least in rodents. With a focus on proalgesic specificities of OxPL, this article discusses, how targeting defined substances of the epilipidome can contribute to mechanism-based therapies against primary and secondary chronic inflammatory or possibly also neuropathic pain.
Inflammation of the central nervous system (CNS) is associated with diseases such as multiple sclerosis, stroke and neurodegenerative diseases. Compromised integrity of the blood-brain barrier (BBB) and increased migration of immune cells into the CNS are the main characteristics of brain inflammation. Clustered protocadherins (Pcdhs) belong to a large family of cadherin-related molecules. Pcdhs are highly expressed in the CNS in neurons, astrocytes, pericytes and epithelial cells of the choroid plexus and, as we have recently demonstrated, in brain microvascular endothelial cells (BMECs). Knockout of a member of the Pcdh subfamily, PcdhgC3, resulted in significant changes in the barrier integrity of BMECs. Here we characterized the endothelial PcdhgC3 knockout (KO) cells using paracellular permeability measurements, proliferation assay, wound healing assay, inhibition of signaling pathways, oxygen/glucose deprivation (OGD) and a pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) treatment. PcdhgC3 KO showed an increased paracellular permeability, a faster proliferation rate, an altered expression of efflux pumps, transporters, cellular receptors, signaling and inflammatory molecules. Serum starvation led to significantly higher phosphorylation of extracellular signal-regulated kinases (Erk) in KO cells, while no changes in phosphorylated Akt kinase levels were found. PcdhgC3 KO cells migrated faster in the wound healing assay and this migration was significantly inhibited by respective inhibitors of the MAPK-, β-catenin/Wnt-, mTOR- signaling pathways (SL327, XAV939, or Torin 2). PcdhgC3 KO cells responded stronger to OGD and TNFα by significantly higher induction of interleukin 6 mRNA than wild type cells. These results suggest that PcdhgC3 is involved in the regulation of major signaling pathways and the inflammatory response of BMECs.
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.
Ischemic stroke is one of the leading causes of death worldwide. It damages neurons and other supporting cellular elements in the brain. However, the impairment is not only confined to the region of assault but the surrounding area as well. Besides, it also brings about damage to the blood-brain barrier (BBB) which in turn leads to microvascular failure and edema. Hence, this necessitates an on-going, continuous search for intervention strategies and effective treatment. Of late, the natural sweetener stevioside proved to exhibit neuroprotective effects and therapeutic benefits against cerebral ischemia-induced injury. Its injectable formulation, isosteviol sodium (STVNA) also demonstrated favorable results. Nonetheless, its effects on the BBB have not yet been investigated to date. As such, this present study was designed to assess the effects of STVNA in our in vitro stroke model of the BBB.The integrity and permeability of the BBB are governed and maintained by tight junction proteins (TJPs) such as claudin-5 and occludin. Our data show increased claudin-5 and occludin expression in oxygen and glucose (OGD)-deprived murine brain capillary cerebellar endothelial cells (cerebEND) after STVNa treatment. Likewise, the upregulation of the transmembrane protein integrin-αv was also observed. Finally, cell volume was reduced with the simultaneous administration of STVNA and OGD in cerebEND cells. In neuropathologies such as stroke, the failure of cell volume control is a major feature leading to loss of cells in the penumbra as well as adverse outcomes. Our initial findings, therefore, point to the neuroprotective effects of STVNA at the BBB in vitro, which warrant further investigation for a possible future clinical intervention.
Objectives
The severity of Coronavirus Disease 2019 (COVID-19) is largely determined by the immune response. First studies indicate altered lymphocyte counts and function. However, interactions of pro- and anti-inflammatory mechanisms remain elusive. In the current study we characterized the immune responses in patients suffering from severe COVID-19-induced acute respiratory distress syndrome (ARDS).
Methods
This was a single-center retrospective study in patients admitted to the intensive care unit (ICU) with confirmed COVID-19 between March 14th and May 28th 2020 (n = 39). Longitudinal data were collected within routine clinical care, including flow-cytometry of lymphocyte subsets, cytokine analysis and growth differentiation factor 15 (GDF-15). Antibody responses against the receptor binding domain (RBD) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike protein were analyzed.
Results
All patients suffered from severe ARDS, 30.8% died. Interleukin (IL)-6 was massively elevated at every time-point. The anti-inflammatory cytokine IL-10 was concomitantly upregulated with IL-6. The cellular response was characterized by lymphocytopenia with low counts of CD8+ T cells, natural killer (NK) and naïve T helper cells. CD8+ T and NK cells recovered after 8 to 14 days. The B cell system was largely unimpeded. This coincided with a slight increase in anti-SARS-CoV-2-Spike-RBD immunoglobulin (Ig) G and a decrease in anti-SARS-CoV-2-Spike-RBD IgM. GDF-15 levels were elevated throughout ICU treatment.
Conclusions
Massively elevated levels of IL-6 and a delayed cytotoxic immune defense characterized severe COVID-19-induced ARDS. The B cell response and antibody production were largely unimpeded. No obvious imbalance of pro- and anti-inflammatory mechanisms was observed, with elevated GDF-15 levels suggesting increased tissue resilience.
Livin/BIRC7 is a member of the inhibitors of apoptosis proteins family, which are involved in tumor development through the inhibition of caspases. Aim was to investigate the expression of livin and other members of its pathway in adrenocortical tumors and in the adrenocortical carcinoma (ACC) cell line NCI-H295R.
The mRNA expression of livin, its isoforms α and β, XIAP, CASP3 and DIABLO was evaluated by qRT-PCR in 82 fresh-frozen adrenal tissues (34 ACC, 25 adenomas = ACA, 23 normal adrenal glands = NAG). Livin protein expression was assessed by immunohistochemistry in 270 paraffin-embedded tissues (192 ACC, 58 ACA, 20 NAG). Livin, CASP3 and cleaved caspase-3 were evaluated in NCI-H295R after induction of livin overexpression.
Relative livin mRNA expression was significantly higher in ACC than in ACA and NAG (0.060 ± 0.116 vs 0.004 ± 0.014 and 0.002 ± 0.009, respectively, p < 0.01), being consistently higher in tumors than in adjacent NAG and isoform β more expressed than α. No significant differences in CASP3, XIAP and DIABLO levels were found among these groups. In immunohistochemistry, livin was localized in both cytoplasm and nuclei. The ratio between cytoplasmic and nuclear staining was significantly higher in ACC (1.51 ± 0.66) than in ACA (0.80 ± 0.35) and NAG (0.88 ± 0.27; p < 0.0001). No significant correlations were observed between livin expression and histopathological parameters or clinical outcome. In NCI-H295R cells, the livin overexpression slightly reduced the activation of CASP3, but did not correlate with cell viability.
In conclusion, livin is specifically over-expressed in ACC, suggesting that it might be involved in adrenocortical tumorigenesis and represent a new molecular marker of malignancy.
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.
Aging is a one-way process associated with profound structural and functional changes in the organism. Indeed, the neuromuscular system undergoes a wide remodeling, which involves muscles, fascia, and the central and peripheral nervous systems. As a result, intrinsic features of tissues, as well as their functional and structural coupling, are affected and a decline in overall physical performance occurs. Evidence from the scientific literature demonstrates that senescence is associated with increased stiffness and reduced elasticity of fascia, as well as loss of skeletal muscle mass, strength, and regenerative potential. The interaction between muscular and fascial structures is also weakened. As for the nervous system, aging leads to motor cortex atrophy, reduced motor cortical excitability, and plasticity, thus leading to accumulation of denervated muscle fibers. As a result, the magnitude of force generated by the neuromuscular apparatus, its transmission along the myofascial chain, joint mobility, and movement coordination are impaired. In this review, we summarize the evidence about the deleterious effect of aging on skeletal muscle, fascial tissue, and the nervous system. In particular, we address the structural and functional changes occurring within and between these tissues and discuss the effect of inflammation in aging. From the clinical perspective, this article outlines promising approaches for analyzing the composition and the viscoelastic properties of skeletal muscle, such as ultrasonography and elastography, which could be applied for a better understanding of musculoskeletal modifications occurring with aging. Moreover, we describe the use of tissue manipulation techniques, such as massage, traction, mobilization as well as acupuncture, dry needling, and nerve block, to enhance fascial repair.
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.
Milk-derived antibacterial peptides (ABPs) are protein fragments with a positive influence on the functions and conditions of a living organism. Milk-derived ABPs have several useful properties important for human health, comprising a significant antibacterial effect against various pathogens, but contain toxic side-effects. These compounds are mainly produced from milk proteins via fermentation and protein hydrolysis. However, they can also be produced using recombinant DNA techniques or organic synthesis. This review describes the role of milk-derived ABPs in modern food biotechnology with an emphasis on their synthesis and applications. Additionally, we also discuss the mechanisms of action and the main bioproperties of ABPs. Finally, we explore future perspectives for improving ABP physicochemical properties and diminishing their toxic side-effects.
Rational drug design of Axl tyrosine kinase type I inhibitors as promising candidates against cancer
(2020)
The high level of Axl tyrosine kinase expression in various cancer cell lines makes it an attractive target for the development of anti-cancer drugs. In this study, we carried out several sets of in silico screening for the ATP-competitive Axl kinase inhibitors based on different molecular docking protocols. The best drug-like candidates were identified, after parental structure modifications, by their highest affinity to the target protein. We found that our newly designed compound R5, a derivative of the R428 patented analog, is the most promising inhibitor of the Axl kinase according to the three molecular docking algorithms applied in the study. The molecular docking results are in agreement with the molecular dynamics simulations using the MM-PBSA/GBSA implicit solvation models, which confirm the high affinity of R5 toward the protein receptor. Additionally, the selectivity test against other kinases also reveals a high affinity of R5 toward ABL1 and Tyro3 kinases, emphasizing its promising potential for the treatment of malignant tumors.
Background
Even though bleeding and thromboembolic events are major complications of extracorporeal membrane oxygenation (ECMO), data on the incidence of venous thrombosis (VT) and thromboembolism (VTE) under ECMO are scarce. This study analyzes the incidence and predictors of VTE in patients treated with ECMO due to respiratory failure.
Methods
Retrospective analysis of patients treated on ECMO in our center from 04/2010 to 11/2015. Patients with thromboembolic events prior to admission were excluded. Diagnosis was made by imaging in survivors and postmortem examination in deceased patients.
Results
Out of 102 screened cases, 42 survivors and 21 autopsy cases [mean age 46.0 ± 14.4 years; 37 (58.7 %) males] fulfilling the above-mentioned criteria were included. Thirty-four patients (54.0 %) underwent ECMO therapy due to ARDS, and 29 patients (46.0 %) with chronic organ failure were bridged to lung transplantation. Despite systemic anticoagulation at a mean PTT of 50.6 ± 12.8 s, [VT/VTE 47.0 ± 12.3 s and no VT/VTE 53.63 ± 12.51 s (p = 0.037)], VT and/or VTE was observed in 29 cases (46.1 %). The rate of V. cava thrombosis was 15/29 (51.7 %). Diagnosis of pulmonary embolism prevailed in deceased patients [5/21 (23.8 %) vs. 2/42 (4.8 %) (p = 0.036)]. In a multivariable analysis, only aPTT and time on ECMO predicted VT/VTE. There was no difference in the incidence of clinically diagnosed VT in ECMO survivors and autopsy findings.
Conclusions
Venous thrombosis and thromboembolism following ECMO therapy are frequent. Quality of anticoagulation and ECMO runtime predicted thromboembolic events.
"
Background:
Until now there has been a reported lack of systematic reports and scientific evaluations of rescue missions during terror attacks. This however is urgently required in order to improve the performance of emergency medical services and to be able to compare different missions with each other. Aim of the presented work was to report the systematic evaluation and the lessons learned from the response to a terror attack that happened in Wuerzburg, Germany in 2016.
Methods:
A team of 14 experts developed a template of quality indicators and operational characteristics, which allow for the description, assessment and comparison of civil emergency rescue missions during mass killing incidents. The entire systematic evaluation process consisted of three main steps. The first step was the systematic data collection according to the quality indicators and operational characteristics. Second was the systematic stratification and assessment of the data. The last step was the prioritisation of the identified weaknesses and the definition of the lessons learned.
Results:
Five important “lessons learned” have been defined. First of all, a comprehensive concept for rescue missions during terror attacks is essential. Furthermore, the establishment of a defined high priority communication infrastructure between the different dispatch centres (“red phone”) is vital. The goal is to secure the continuity of information between a few well-defined individuals. Thirdly, the organization of the incident scene needs to be commonly decided and communicated between police, medical services and fire services during the mission. A successful mission tactic requires continuous flux of reports to the on-site command post. Therefore, a predefined and common communication infrastructure for all operational forces is a crucial point. Finally, all strategies need to be extensively trained before the real life scenario hits.
Conclusion:
According to a systematic evaluation, we defined the lessons learned from a terror attack in 2016. Further systematic reports and academic work surrounding life threatening rescue missions and mass killing incidents are needed in order to ultimately improve such mission outcomes. In the future, a close international collaboration might help to find the best database to report and evaluate major incidents but also mass killing events.
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.
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.
After a large outbreak in Brazil, novel drugs against Zika virus became extremely necessary. Evaluation of virus-based pharmacological strategies concerning essential host factors brought us to the idea that targeting the Axl receptor by blocking its dimerization function could be critical for virus entry. Starting from experimentally validated compounds, such as RU-301, RU-302, warfarin, and R428, we identified a novel compound 2′ (R428 derivative) to be the most potent for this task amongst a number of alternative compounds and leads. The improved affinity of compound 2′ was confirmed by molecular docking as well as molecular dynamics simulation techniques using implicit solvation models. The current study summarizes a new possibility for inhibition of the Axl function as a potential target for future antiviral therapies.
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.
Non-steroidal antiinflammatory drugs are most commonly used for inflammatory and postoperative pain. But they lack effectiveness and specificity, leading to severe side effects, like gastric ulcers, asthma and severe bleeding. Oxidized 1-palmitoyl-2-arachinidonoyl-sn-glycero-3-phosphocholine (OxPAPC) plays an important role in inflammatory pain. PAPC is a common phosphatidylcholine of membranes, which can be oxidized by reactive oxygen species. In preliminary experiments, our group found that local injection of OxPAPC in rat paws induces hyperalgesia.
In this study we examined the effect of OxPAPC on transient receptor potential A1 (TRPA1), an ion channel expressed in C-fiber neurons. Furthermore, we investigated if intracellular cysteine residues of TRPA1 were necessary for agonist-channel-interactions and if a subsequent TRPA1 activation could be prevented by OxPAPC scavengers.
To answer these questions, we performed calcium imaging using HEK-293 cells stably expressing hTRPA1, or transiently expressing the triple mutant channel hTRPA1-3C and naïve DRG neurons. Cells were incubated with the ratiometric, fluorescent dye Fura-2/AM and stimulated with OxPAPC. The change of light emission after excitation with 340 and 380 nm wavelengths allowed conclusions regarding changes of intracellular calcium concentrations after TRPA1 activation.
In our investigation we proved evidence that OxPAPC activates TRPA1, which caused a flow of calcium ions into the cytoplasm. The TRPA1-specific channel blocker HC-030031 eliminated this agonist-induced response. TRPA1-3C was not completely sensitive to OxPAPC. The peptide D-4F and the monoclonal antibody E06 neutralized OxPAPC-induced TRPA1 activation.
In this work, the importance of OxPAPC as a key mediator of inflammatory pain and as a promising target for drug design is highlighted. Our results indicate that TRPA1 activation by OxPAPC involves cysteine-dependent mechanisms, but there are other, cysteine-independent activation mechanisms as well. Potential pharmaceuticals for the treatment of inflammatory pain are D-4F and E06, whose efficiency has recently been confirmed in the animal model by our research group.
Central nervous system dysfunction is an important cause of morbidity and mortality in patients with human immunodeficiency virus type 1 (HIV-1) infection and acquired immunodeficiency virus syndrome (AIDS). Patients with AIDS are usually affected by HIV-associated encephalitis (HIVE) with viral replication limited to cells of monocyte origin. To examine the molecular mechanisms underlying HIVE-induced dementia, the GSE4755 Affymetrix data were obtained from the Gene Expression Omnibus database and the differentially expressed genes (DEGs) between the samples from AIDS patients with and without apparent features of HIVE-induced dementia were identified. In addition, protein–protein interaction networks were constructed by mapping DEGs into protein–protein interaction data to identify the pathways that these DEGs are involved in. The results revealed that the expression of 1,528 DEGs is mainly involved in the immune response, regulation of cell proliferation, cellular response to inflammation, signal transduction, and viral replication cycle. Heat-shock protein alpha, class A member 1 (HSP90AA1), and fibronectin 1 were detected as hub nodes with degree values >130. In conclusion, the results indicate that HSP90A and fibronectin 1 play important roles in HIVE pathogenesis.
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.
In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell® system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCN-TFITC rapid dissociation as an intermediate phase.
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.
Multiple antenatal dexamethasone treatment alters brain vessel differentiation in newborn mouse pups
(2015)
Antenatal steroid treatment decreases morbidity and mortality in premature infants through the maturation of lung tissue, which enables sufficient breathing performance. However, clinical and animal studies have shown that repeated doses of glucocorticoids such as dexamethasone and betamethasone lead to long-term adverse effects on brain development. Therefore, we established a mouse model for antenatal dexamethasone treatment to investigate the effects of dexamethasone on brain vessel differentiation towards the blood-brain barrier (BBB) phenotype, focusing on molecular marker analysis. The major findings were that in total brains on postnatal day (PN) 4 triple antenatal dexamethasone treatment significantly downregulated the tight junction protein claudin-5, the endothelial marker Pecam-1/CD31, the glucocorticoid receptor, the NR1 subunit of the N-methyl-D-aspartate receptor, and Abc transporters (Abcb1a, Abcg2 Abcc4). Less pronounced effects were found after single antenatal dexamethasone treatment and in PN10 samples. Comparisons of total brain samples with isolated brain endothelial cells together with the stainings for Pecam-1/CD31 and claudin-5 led to the assumption that the morphology of brain vessels is affected by antenatal dexamethasone treatment at PN4. On the mRNA level markers for angiogenesis, the sonic hedgehog and the Wnt pathway were downregulated in PN4 samples, suggesting fundamental changes in brain vascularization and/or differentiation. In conclusion, we provided a first comprehensive molecular basis for the adverse effects of multiple antenatal dexamethasone treatment on brain vessel differentiation.
The blood-brain barrier (BBB), made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI), cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD) is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH) and nitric oxide (NO) into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (I L)-6, IL-1\(\alpha\) chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-\(\alpha\) also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glutl expression, and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models.
The volatile anesthetic desflurane (DES) effectively reduces cardiac infarct size following experimental ischemia/reperfusion injury in the mouse heart. We hypothesized that endogenous estrogens play a role as mediators of desflurane-induced preconditioning against myocardial infarction. In this study, we tested the hypothesis that desflurane effects local estrogen synthesis by modulating enzyme aromatase expression and activity in the mouse heart. Aromatase metabolizes testosterone to 17b- estradiol (E2) and thereby significantly contributes to local estrogen synthesis. We tested aromatase effects in acute myocardial infarction model in male mice. The animals were randomized and subjected to four groups which were pre-treated with the selective aromatase inhibitor anastrozole (A group) and DES alone (DES group) or in combination (A+DES group) for 15 minutes prior to surgical intervention whereas the control group received 0.9% NaCl (CON group). All animals were subjected to 45 minutes ischemia following 180 minutes reperfusion. Anastrozole blocked DES induced preconditioning and increased infarct size compared to DES alone (37.94615.5% vs. 17.163.62%) without affecting area at risk and systemic hemodynamic parameters following ischemia/reperfusion. Protein localization studies revealed that aromatase was abundant in the murine cardiovascular system with the highest expression levels in endothelial and smooth muscle cells. Desflurane application at pharmacological concentrations efficiently upregulated aromatase expression in vivo and in vitro. We conclude that desflurane efficiently regulates aromatase expression and activity which might lead to increased local estrogen synthesis and thus preserve cellular integrity and reduce cardiac damage in an acute myocardial infarction model.
Antinociceptive pathways are activated in the periphery in inflammatory pain, for instance resolvins and opioid peptides. Resolvins are biosynthesized from omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. Resolvin D1 (RvD1) and resolvin E1 (RvE1) initiate the resolution of inflammation and control of hypersensitivity via induction of anti-inflammatory signaling cascades. RvD1 binds to lipoxin A4/annexin-A1 receptor/formyl-peptide receptor 2 (ALX/FPR2), RvE1 to chemerin receptor 23 (ChemR23). Antinociception of RvD1 is mediated by interaction with transient receptor potential channels ankyrin 1 (TRPA1). Endogenous opioid peptides are synthesized and released from leukocytes in the tissue and bind to opioid receptors on nociceptor terminals. Here, we further explored peripheral mechanisms of RvD1 and chemerin (Chem), the ligand of ChemR23, in complete Freund’s adjuvant (CFA)-induced hindpaw inflammation in male Wistar rats. RvD1 and Chem ameliorated CFA-induced hypersensitivity in early and late inflammatory phases. This was prevented by peripheral blockade of the μ-opioid peptide receptor (MOR) using low dose local naloxone or by local injection of anti-β-endorphin and anti-met-enkephalin (anti-ENK) antibodies. Naloxone also hindered antinociception by the TRPA1 inhibitor HC-030031. RvD1 did not stimulate the release of β-endorphin from macrophages and neutrophils, nor did RvD1 itself activate G-proteins coupled MOR or initiate β-arrestin recruitment to the membrane. TRPA1 blockade by HC-030031 in inflammation in vivo as well as inhibition of the TRPA1-mediated calcium influx in dorsal root ganglia neurons in vitro was hampered by naloxone. Peripheral application of naloxone alone in vivo already lowered mechanical nociceptive thresholds. Therefore, either a perturbation of the balance of endogenous pro- and antinociceptive mechanisms in early and late inflammation, or an interaction of TRPA1 and opioid receptors weaken the antinociceptive potency of RvD1 and TRPA1 blockers.
Phospholipids occurring in cell membranes and lipoproteins are converted into oxidized phospholipids (OxPL) by oxidative stress promoting atherosclerotic plaque formation. Here, OxPL were characterized as novel targets in acute and chronic inflammatory pain. Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (OxPAPC) and its derivatives were identified in inflamed tissue by mass spectrometry and binding assays. They elicited calcium influx, hyperalgesia and induced pro-nociceptive peptide release. Genetic, pharmacological and mass spectrometric evidence in vivo as well as in vitro confirmed the role of transient receptor potential channels (TRPA1 and TRPV1) as OxPAPC targets. Treatment with the monoclonal antibody E06 or with apolipoprotein A-I mimetic peptide D-4F, capturing OxPAPC in atherosclerosis, prevented inflammatory hyperalgesia, and in vitro TRPA1 activation. Administration of D-4F or E06 to rats profoundly ameliorated mechanical hyperalgesia and inflammation in collagen-induced arthritis. These data reveal a clinically relevant role for OxPAPC in inflammation offering therapy for acute and chronic inflammatory pain treatment by scavenging OxPAPC.
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.
Neuropathic pain, caused by a lesion in the somatosensory system, is a severely impairing mostly chronic disease. While its underlying molecular mechanisms are not thoroughly understood, neuroimmune interactions as well as changes in the pain pathway such as sensitization of nociceptors have been implicated. It has been shown that not only are different cell types involved in generation and maintenance of neuropathic pain, like neurons, immune and glial cells, but, also, intact adjacent neurons are relevant to the process. Here, we describe an experimental approach to discriminate damaged from intact adjacent neurons in the same dorsal root ganglion (DRG) using differential fluorescent neuronal labelling and fluorescence-activated cell sorting (FACS). Two fluorescent tracers, Fluoroemerald (FE) and 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI), were used, whose properties allow us to distinguish between damaged and intact neurons. Subsequent sorting permitted transcriptional analysis of both groups. Results and qPCR validation show a strong regulation in damaged neurons versus contralateral controls as well as a moderate regulation in adjacent neurons. Data for damaged neurons reveal an mRNA expression pattern consistent with established upregulated genes like galanin, which supports our approach. Moreover, novel genes were found strongly regulated such as corticotropinreleasing hormone (CRH), providing novel targets for further research. Differential fluorescent neuronal labelling and sorting allows for a clear distinction between primarily damaged neuropathic neurons and "bystanders," thereby facilitating a more detailed understanding of their respective roles in neuropathic processes in the DRG.
The Unrecognized Effects of Phosphodiesterase 4 on Epithelial Cells in Pulmonary Inflammation
(2015)
Acute pulmonary inflammation is characterized by migration of polymorphonuclear neutrophils (PMNs) into the different compartments of the lung, passing an endothelial and epithelial barrier. Recent studies showed evidence that phosphodiesterase (PDE) 4-inhibitors stabilized endothelial cells. PDE4B and PDE4D subtypes play a pivotal role in inflammation, whereas blocking PDE4D is suspected to cause gastrointestinal side effects. We thought to investigate the particular role of the PDE4-inhibitors roflumilast and rolipram on lung epithelium. Acute pulmonary inflammation was induced by inhalation of LPS. PDE4-inhibitors were administered i.p. or nebulized after inflammation. The impact of PDE4-inhibitors on PMN migration was evaluated in vivo and in vitro. Microvascular permeability, cytokine levels, and PDE4B and PDE4D expression were analyzed. In vivo, both PDE4-inhibitors decreased transendothelial and transepithelial migration even when administered after inflammation, whereas roflumilast showed a superior effect compared to rolipram on the epithelium. Both inhibitors decreased TNF\(\alpha\), IL6, and CXCL2/3. CXCL1, the strong PMN chemoattractant secreted by the epithelium, was significantly more reduced by roflumilast. In vitro assays with human epithelium also emphasized the pivotal role of roflumilast on the epithelium. Additionally, LPS-induced stress fibers, an essential requirement for a direct migration of PMNs into the alveolar space, were predominantly reduced by roflumilast. Expression of PDE4B and PDE4D were both increased in the lungs by LPS, PDE4-inhibitors decreased mainly PDE4B. The topical administration of PDE4-inhibitors was also effective in curbing down PMN migration, further highlighting the clinical potential of these compounds. In pulmonary epithelial cells, both subtypes were found coexistent around the nucleus and the cytoplasm. In these epithelial cells, LPS increased PDE4B and, to a lesser extend, PDE4D, whereas the effect of the inhibitors was prominent on the PDE4B subtype. In conclusion, we determined the pivotal role of the PDE4-inhibitor roflumilast on lung epithelium and emphasized its main effect on PDE4B in hyperinflammation.
Background
There are not enough clinical data from rare critical events to calculate statistics to decide if the management of actual events might be below what could reasonably be expected (i.e. was an outlier).
Objectives
In this project we used simulation to describe the distribution of management times as an approach to decide if the management of a simulated obstetrical crisis scenario could be considered an outlier.
Design
Twelve obstetrical teams managed 4 scenarios that were previously developed. Relevant outcome variables were defined by expert consensus. The distribution of the response times from the teams who performed the respective intervention was graphically displayed and median and quartiles calculated using rank order statistics.
Results
Only 7 of the 12 teams performed chest compressions during the arrest following the 'cannot intubate/cannot ventilate' scenario. All other outcome measures were performed by at least 11 of the 12 teams. Calculation of medians and quartiles with 95% CI was possible for all outcomes. Confidence intervals, given the small sample size, were large.
Conclusion
We demonstrated the use of simulation to calculate quantiles for management times of critical event. This approach could assist in deciding if a given performance could be considered normal and also point to aspects of care that seem to pose particular challenges as evidenced by a large number of teams not performing the expected maneuver. However sufficiently large sample sizes (i.e. from a national data base) will be required to calculate acceptable confidence intervals and to establish actual tolerance limits.
Background: Remote ischemic conditioning is gaining interest as potential method to induce resistance against ischemia reperfusion injury in a variety of clinical settings. We performed a systematic review and meta-analysis to investigate whether remote ischemic conditioning reduces mortality, major adverse cardiovascular events, length of stay in hospital and in the intensive care unit and biomarker release in patients who suffer from or are at risk for ischemia reperfusion injury.
Methods and Results: Medline, EMBASE and Cochrane databases were searched for randomized clinical trials comparing remote ischemic conditioning, regardless of timing, with no conditioning. Two investigators independently selected suitable trials, assessed trial quality and extracted data. 23 studies in patients undergoing cardiac surgery (15 studies), percutaneous coronary intervention (four studies) and vascular surgery (four studies), comprising in total 1878 patients, were included in this review. Compared to no conditioning, remote ischemic conditioning did not reduce mortality (odds ratio 1.22 [95% confidence interval 0.48, 3.07]) or major adverse cardiovascular events (0.65 [0.38, 1.14]). However, the incidence of myocardial infarction was reduced with remote ischemic conditioning (0.50 [0.31, 0.82]), as was peak troponin release (standardized mean difference -0.28 [-0.47, -0.09]).
Conclusion: There is no evidence that remote ischemic conditioning reduces mortality associated with ischemic events; nor does it reduce major adverse cardiovascular events. However, remote ischemic conditioning did reduce the incidence of peri-procedural myocardial infarctions, as well as the release of troponin.
Background
Precise and complete documentation of in-hospital cardiopulmonary resuscitations is important but data quality can be poor. In the present study, we investigated the effect of a tablet-based application for real-time resuscitation documentation used by the emergency team leader on documentation quality and clinical performance of the emergency team.
Methods
Senior anaesthesiologists either used the tablet-based application during the simulated resuscitation for documentation and also used the application for the final documentation or conducted the full documentation at the end of the scenario using the local hospital information system. The latter procedure represents the current local documentation method. All scenarios were video recorded. To assess the documentation, we compared the precision of intervention delivery times, documentation completeness, and final documentation time. To assess clinical performance, we compared adherence to guidelines for defibrillation and adrenaline administration, the no-flow fraction, and the time to first defibrillation.
Results
The results showed significant benefits for the tablet-based application compared to the hospital information system for precision of the intervention delivery times, the final documentation time, and the no-flow fraction. We observed no differences between the groups for documentation completeness, adherence to guidelines for defibrillation and adrenaline administration, and the time to first defibrillation.
Discussion
In the presented study, we observed that a tablet-based application can improve documentation data quality. Furthermore, we demonstrated that a well-designed application can be used in real-time by a member of the emergency team with possible beneficial effects on clinical performance.
Conclusion
The present evaluation confirms the advantage of tablet-based documentation tools and also shows that the application can be used by an active member of an emergency team without compromising clinical performance.
Background
Enteric glial cells (EGCs) are the main constituent of the enteric nervous system and share similarities with astrocytes from the central nervous system including their reactivity to an inflammatory microenvironment. Previous studies on EGC pathophysiology have specifically focused on mucosal glia activation and its contribution to mucosal inflammatory processes observed in the gut of inflammatory bowel disease (IBD) patients. In contrast knowledge is scarce on intestinal inflammation not locally restricted to the mucosa but systemically affecting the intestine and its effect on the overall EGC network.
Methods and Results
In this study, we analyzed the biological effects of a systemic LPS-induced hyperinflammatory insult on overall EGCs in a rat model in vivo, mimicking the clinical situation of systemic inflammation response syndrome (SIRS). Tissues from small and large intestine were removed 4 hours after systemic LPS-injection and analyzed on transcript and protein level. Laser capture microdissection was performed to study plexus-specific gene expression alterations. Upon systemic LPS-injection in vivo we observed a rapid and dramatic activation of Glial Fibrillary Acidic Protein (GFAP)-expressing glia on mRNA level, locally restricted to the myenteric plexus. To study the specific role of the GFAP subpopulation, we established flow cytometry-purified primary glial cell cultures from GFAP promotor-driven EGFP reporter mice. After LPS stimulation, we analyzed cytokine secretion and global gene expression profiles, which were finally implemented in a bioinformatic comparative transcriptome analysis. Enriched GFAP+ glial cells cultured as gliospheres secreted increased levels of prominent inflammatory cytokines upon LPS stimulation. Additionally, a shift in myenteric glial gene expression profile was induced that predominantly affected genes associated with immune response.
Conclusion and Significance
Our findings identify the myenteric GFAP-expressing glial subpopulation as particularly susceptible and responsive to acute systemic inflammation of the gut wall and complement knowledge on glial involvement in mucosal inflammation of the intestine.
Functional and structural characterization of axonal opioid receptors as targets for analgesia
(2016)
Background
Opioids are the gold standard for the treatment of acute pain despite serious side effects in the central and enteric nervous system. µ-opioid receptors (MOPs) are expressed and functional at the terminals of sensory axons, when activated by exogenous or endogenous ligands. However, the presence and function of MOP along nociceptive axons remains controversial particularly in naïve animals. Here, we characterized axonal MOPs by immunofluorescence, ultrastructural, and functional analyses. Furthermore, we evaluated hypertonic saline as a possible enhancer of opioid receptor function.
Results
Comparative immunolabeling showed that, among several tested antibodies, which all provided specific MOP detection in the rat central nervous system (CNS), only one monoclonal MOP-antibody yielded specificity and reproducibility for MOP detection in the rat peripheral nervous system including the sciatic nerve. Double immunolabeling documented that MOP immunoreactivity was confined to calcitonin gene-related peptide (CGRP) positive fibers and fiber bundles. Almost identical labeling and double labeling patterns were found using mcherry-immunolabeling on sciatic nerves of mice producing a MOP-mcherry fusion protein (MOP-mcherry knock-in mice). Preembedding immunogold electron microscopy on MOP-mcherry knock-in sciatic nerves indicated presence of MOP in cytoplasm and at membranes of unmyelinated axons. Application of [D-Ala\(^2\), N-MePhe\(^4\), Gly-ol]-enkephalin (DAMGO) or fentanyl dose-dependently inhibited depolarization-induced CGRP release from rat sciatic nerve axons ex vivo, which was blocked by naloxone. When the lipophilic opioid fentanyl was applied perisciatically in naïve Wistar rats, mechanical nociceptive thresholds increased. Subthreshold doses of fentanyl or the hydrophilic opioid DAMGO were only effective if injected together with hypertonic saline. In vitro, using β-arrestin-2/MOP double-transfected human embryonic kidney cells, DAMGO as well as fentanyl lead to a recruitment of β-arrestin-2 to the membrane followed by a β-arrestin-2 reappearance in the cytosol and MOP internalization. Pretreatment with hypertonic saline prevented MOP internalization.
Conclusion
MOPs are present and functional in the axonal membrane from naïve animals. Hypertonic saline acutely decreases ligand-induced internalization of MOP and thereby might improve MOP function. Further studies should explore potential clinical applications of opioids together with enhancers for regional analgesia.
Following the early experiences in aviation, medical simulation has rapidly
evolved into one of the most novel educational tools of the last three decades. In addition to its
use in training individuals or teams in crisis resource management, simulation has been studied as
a tool to evaluate technical and non-technical skills of individuals as well as, more recently,
entire medical teams.
It is usually fairly difficult to obtain clinical reference data from critical events to refute
claims that the management of actual events fell below what could reasonably be expected and we
demonstrated the use of rank order statistics to calculate quantiles with confidence limits for
management times of critical obstetrical events using data from realistic simulation. This approach
could be used to describe the distribution of treatment times in order to assist in deciding what
performance may constitute an outlier. It can also identify particular challenges of clinical
practice and allow the development of educational curricula. While the information derived from
simulation has to be interpreted with a high degree of caution for a clinical context, it may
represent a further ‘added value’ or important step in establishing simulation as a training tool
and to provide information that could be used in an appropriate clinical context for adverse
events. Large amounts of data (such as from a simulation registry) would allow the calculation of
acceptable confidence intervals for the required
outcome parameters as well as actual tolerance limits.
P-glycoprotein (P-gp)-mediated efflux system plays an important role to maintain chemical balance in mammalian cells for endogenous and exogenous chemical compounds. However, despite the extensive characterisation of P-gp potential interaction with drug-like molecules, the interaction of carbon nanoparticles with this type of protein molecule is poorly understood. Thus, carbon nanoparticles were analysed, such as buckminsterfullerenes (C20, C60, C70), capped armchair single-walled carbon nanotube (SWCNT or C168), and P-gp interactions using different molecular docking techniques, such as gradient optimisation algorithm (ADVina), Lamarckian genetic algorithm (FastDock), and shape-based approach (PatchDock) to estimate the binding affinities between these structures. The theoretical results represented in this work show that fullerenes might be P-gp binders because of low levels of Gibbs free energy of binding (ΔG) and potential of mean force (PMF) values. Furthermore, the SWCNT binding is energetically unfavourable, leading to a total decrease in binding affinity by elevation of the residual area (Ares), which also affects the π-π stacking mechanisms. Further, the obtained data could potentially call experimental studies using carbon nanostructures, such as SWCNT for development of drug delivery vehicles, to administer and assess drug-like chemical compounds to the target cells since organisms probably did not develop molecular sensing elements to detect these types of carbon molecules.
Background. Nitric oxide (NO)-signal transduction plays an important role in renal ischemia/reperfusion (I/R) injury. NO produced by endothelial NO-synthase (eNOS) has protective functions whereas NO from inducible NO-synthase (iNOS) induces impairment. Rosiglitazone (RGZ), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist exerted beneficial effects after renal I/R injury, so we investigated whether this might be causally linked with NOS imbalance. Methods. RGZ (5 mg/kg) was administered i.p. to SD-rats (f) subjected to bilateral renal ischemia (60 min). Following 24 h of reperfusion, inulin-and PAH-clearance as well as PAH-net secretion were determined. Morphological alterations were graded by histopathological scoring. Plasma NOx-production was measured. eNOS and iNOS expression was analyzed by qPCR. Cleaved caspase 3 (CC3) was determined as an apoptosis indicator and ED1 as a marker of macrophage infiltration in renal tissue. Results. RGZ improves renal function after renal I/R injury (PAH-/inulin-clearance, PAH-net secretion) and reduces histomorphological injury. Additionally, RGZ reduces NOx plasma levels, ED-1 positive cell infiltration and CC3 expression. iNOS-mRNA is reduced whereas eNOS-mRNA is increased by RGZ. Conclusion. RGZ has protective properties after severe renal I/R injury. Alterations of the NO pathway regarding eNOS and iNOS could be an explanation of the underlying mechanism of RGZ protection in renal I/R injury.
Neuropathic pain, caused by neuronal damage, is a severely impairing mostly chronic condition. Its underlying molecular mechanisms have not yet been thoroughly understood in their variety. In this doctoral thesis, I investigated the role of microRNAs (miRNAs) in a murine model of peripheral neuropathic pain. MiRNAs are small, non-coding RNAs known to play a crucial role in post-transcriptional gene regulation, mainly in cell proliferation and differentiation. Initially, expression patterns in affected dorsal root ganglia (DRG) at different time points after setting a peripheral nerve lesion were studied. DRG showed an increasingly differential expression pattern over the course of one week. Interestingly, a similar effect, albeit to a smaller extent, was observed in corresponding contralateral ganglia. Five miRNA (miR-124, miR-137, miR-183, miR-27b, and miR-505) were further analysed. qPCR, in situ hybridization, and bioinformatical analysis point towards a role for miR-137 and -183 in neuropathic pain as both were downregulated. Furthermore, miR-137 is shown to be specific for non-peptidergic non-myelinated nociceptors (C fibres) in DRG. As the ganglia consist of highly heterocellular tissue, I also developed a neuron-specific approach. Primarily damaged neurons were separated from intact adjacent neurons using fluorescence-activated cell-sorting and their gene expression pattern was analysed using a microarray. Thereby, not only were information obtained about mRNA expression in both groups but, by bioinformatical tools, also inferences on miRNA involvement. The general expression pattern was consistent with previous findings. Still, several genes were found differentially expressed that had not been described in this context before. Among these are corticoliberin or cation-regulating proteins like Otopetrin1. Bioinformatical data conformed, in part, to results from whole DRG, e.g. they implied a down-regulation of miR-124, -137, and -183. However, these results were not significant.
In summary, I found that a) miRNA expression in DRG is influenced by nerve lesions typical of neuropathic pain and that b) these changes develop simultaneously to over-expression of galanin, a marker for neuronal damage. Furthermore, several miRNAs (miR-183, -137) exhibit distinct expression patterns in whole-DRG as well as in neuron-specific approaches. Therefore, further investigation of their possible role in initiation and maintenance of neuropathic pain seems promising.
Finally, the differential expression of genes like Corticoliberin or Otopetrin 1, previously not described in neuropathic pain, has already resulted in follow-up projects.
The dispersion routes of cyclodextrin complexes with nicardipine (NC), such as hydrophilic hydroxypropyl-\(\beta\)-cyclodextrin (NC/HP\(\beta\)CD) and hydrophobic triacetyl-\(\beta\)-cyclodextrin (NC/TA\(\beta\)CD), through the body for controlled drug delivery and sustained release have been examined. The two-compartment pharmacokinetic model described the mechanisms of how the human body handles with ingestion of NC-cyclodextrin complexes in gastrointestinal tract (GI), distribution in plasma, and their metabolism in the liver. The model showed that drug bioavailability was significantly improved after oral administration of cyclodextrin complexes. The mathematical significance of this study to predict nicardipine delivery using pharmacokinetic two-compartment mathematical model with linear ordinary differential equations (ODE) approach represents a valuable tool to emphasize its effectiveness and metabolizing rate and diminish the side effects.
Glucocorticoids (GCs) are steroid hormones that have inflammatory and immunosuppressive effects on a wide variety of cells. They are used as therapy for inflammatory disease and as a common agent against edema. The blood brain barrier (BBB), comprising microvascular endothelial cells, serves as a permeability screen between the blood and the brain. As such, it maintains homeostasis of the central nervous system (CNS). In many CNS disorders, BBB integrity is compromised. GC treatment has been demonstrated to improve the tightness of the BBB. The responses and effects of GCs are mediated by the ubiquitous GC receptor (GR). Ligand-bound GR recognizes and binds to the GC response element located within the promoter region of target genes. Transactivation of certain target genes leads to improved barrier properties of endothelial cells. In this review, we deal with the role of GCs in endothelial cell barrier function. First, we describe the mechanisms of GC action at the molecular level. Next, we discuss the regulation of the BBB by GCs, with emphasis on genes targeted by GCs such as occludin, claudins and VE-cadherin. Finally, we present currently available GC therapeutic strategies and their limitations.
Background
Aim of this study was to evaluate prognosis of severely injured patients.
Methods
All severely injured patients with an Injury Severity Score (ISS) ≥ 50 were identified in a 6-year-period between 2000 and 2005 in German Level 1 Trauma Center Murnau. Data was evaluated from German Trauma Registry and Polytrauma Outcome Chart of the German Society for Trauma Surgery and a personal interview to assess working ability and disability and are presented as average.
Results
88 out of 1435 evaluated patients after severe polytrauma demonstrated an ISS ≥ 50 (6.5%), among them 23% women and 77% men. 66 patients (75%) had an ISS of 50-60, 14 (16%) 61-70, and 8 (9%) ≥ 70. In 27% of patients trauma was caused by motor bike accidents. 3.6 body regions were involved. Patients had to be operated 5.3 times and were treated 23 days in the ICU and stayed 73 days in hospital. Mortality rate was 36% and rate of multi-organ failure 28%. 15% of patients demonstrated severe senso-motoric dysfunction as well as residues of severe head injury. 25% recovered well or at least moderately. 29 out of 56 survivors answered the POLO-chart. A personal interview was performed with 13 patients. The state of health was at least moderate in 72% of patients. In 48% interpersonal problems and in 41% severe pain was observed. In 57% of patients problems with working ability regarding duration, as well as quantitative and qualitative performance were observed. Symptoms of post-traumatic stress disorder were found in 41%. The more distal the lesions were located (foot/ankle) the more functional disability affected daily life. In only 15%, working ability was not impaired. 8 out of 13 interviewed patients demonstrated complete work disability.
Conclusions
Even severely injured patients after multiple trauma have a good prognosis. The ISS is an established tool to assess severity and prognosis of trauma, whereas prediction of clinical outcome cannot be deducted from this score.
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.
P-glycoprotein (P-gp) is an ATP (adenosine triphosphate)-binding cassette transporter that causes multidrug resistance of various chemotherapeutic substances by active efflux from mammalian cells. P-gp plays a pivotal role in limiting drug absorption and distribution in different organs, including the intestines and brain. Thus, the prediction of P-gp–drug interactions is of vital importance in assessing drug pharmacokinetic and pharmacodynamic properties. To find the strongest P-gp blockers, we performed an in silico structure-based screening of P-gp inhibitor library (1,300 molecules) by the gradient optimization method, using polynomial empirical scoring (POLSCORE) functions. We report a strong correlation (r2=0.80, F=16.27, n=6, P<0.0157) of inhibition constants (Kiexp or pKiexp; experimental Ki or negative decimal logarithm of Kiexp) converted from experimental IC50 (half maximal inhibitory concentration) values with POLSCORE-predicted constants (KiPOLSCORE or pKiPOLSCORE), using a linear regression fitting technique. The hydrophobic interactions between P-gp and selected drug substances were detected as the main forces responsible for the inhibition effect. The results showed that this scoring technique might be useful in the virtual screening and filtering of databases of drug-like compounds at the early stage of drug development processes.
The blood–brain barrier choline transporter (BBB-ChT) may have utility as a drug delivery vector to the central nervous system (CNS). We therefore initiated molecular docking studies with the AutoDock and AutoDock Vina (ADVina) algorithms to develop predictive models for compound screening and to identify structural features important for binding to this transporter. The binding energy predictions were highly correlated with r2=0.88, F=692.4, standard error of estimate =0.775, and P-value<0.0001 for selected BBB-ChT-active/inactive compounds (n=93). Both programs were able to cluster active (Gibbs free energy of binding <−6.0 kcal*mol-1) and inactive (Gibbs free energy of binding >−6.0 kcal*mol-1) molecules and dock them significantly better than at random with an area under the curve value of 0.86 and 0.84, respectively. In ranking smaller molecules with few torsional bonds, a size-related bias in scoring producing false-negative outcomes was detected. Finally, important blood–brain barrier parameters, such as the logBBpassive and logBBactive values, were assessed to predict compound transport to the CNS accurately. Knowledge gained from this study is useful to better understand the binding requirements in BBB-ChT, and until such time as its crystal structure becomes available, it may have significant utility in developing a highly predictive model for the rational design of drug-like compounds targeted to the brain.
Epithelial and endothelial cells (EC) are building paracellular barriers which protect the tissue from the external and internal environment. The blood-brain barrier (BBB) consisting of EC, astrocyte end-feet, pericytes and the basal membrane is responsible for the protection and homeostasis of the brain parenchyma. In vitro BBB models are common tools to study the structure and function of the BBB at the cellular level. A considerable number of different in vitro BBB models have been established for research in different laboratories to date. Usually, the cells are obtained from bovine, porcine, rat or mouse brain tissue (discussed in detail in the review by Wilhelm et al. 1). Human tissue samples are available only in a restricted number of laboratories or companies 2,3. While primary cell preparations are time consuming and the EC cultures can differ from batch to batch, the establishment of immortalized EC lines is the focus of scientific interest.
Here, we present a method for establishing an immortalized brain microvascular EC line from neonatal mouse brain. We describe the procedure step-by-step listing the reagents and solutions used. The method established by our lab allows the isolation of a homogenous immortalized endothelial cell line within four to five weeks. The brain microvascular endothelial cell lines termed cEND 4 (from cerebral cortex) and cerebEND 5 (from cerebellar cortex), were isolated according to this procedure in the Förster laboratory and have been effectively used for explanation of different physiological and pathological processes at the BBB. Using cEND and cerebEND we have demonstrated that these cells respond to glucocorticoid- 4,6-9 and estrogen-treatment 10 as well as to pro-infammatory mediators, such as TNFalpha 5,8. Moreover, we have studied the pathology of multiple sclerosis 11 and hypoxia 12,13 on the EC-level. The cEND and cerebEND lines can be considered as a good tool for studying the structure and function of the BBB, cellular responses of ECs to different stimuli or interaction of the EC with lymphocytes or cancer cells.
Purpose
Once open abdomen therapy has succeeded, the problem of closing the abdominal wall must be addressed. We present a new four-stage procedure involving the application of a two-component mesh and vacuum conditioning for abdominal wall closure of even large defects. The aim is to prevent the development of a giant ventral hernia and the eventual need for the repair of the abdominal wall.
Methods
Nineteen of 62 patients treated by open abdomen over a two-year period could not receive primary abdominal wall closure. To achieve closure in these patients, we applied the following four-stage procedure: stage 1: abdominal damage control and conditioning of the abdominal wall; stage 2: attachment of a tailored two-component mesh of polyglycolic acid (PGA) and large pore polypropylene (PP) in intraperitoneal position (IPOM) plus placement of a vacuum bandage; stage 3: vacuum therapy for 3–4 weeks to allow granulation of the mesh and optimization of dermatotraction; stage 4: final skin suture. During stage 3, eligible patients were weaned from respirator and mobilized.
Results
The abdominal wall gap in the 19 patients ranged in size from 240 cm2 to more than 900 cm2. An average of 3.44 vacuum dressing changes over 19 days were required to achieve 60–100 % granulation of the surface area, so final skin suture could be made. Already in stage 3, 14 patients (73.68 %) could be weaned from respirator an average of 6.78 days after placement of the two-component mesh; 6 patients (31.57 %) could be mobilized on the edge of the bed and/or to a bedside chair after an average of 13 days. No mesh-related hematomas, seromas, or intestinal fistulas were observed.
Conclusion
The four-stage procedure presented here is a viable option for achieving abdominal wall closure in patients treated with open abdomen, enabling us to avoid the development of planned giant ventral hernias. It has few complications and has the special advantage of allowing mobilization of the patients before final skin closure. Long-term course in a large number of patients must still confirm this result.
Balanced hydroxyethylstarch (HES 130/0.4) impairs kidney function in-vivo without inflammation
(2015)
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
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.
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.
Background
Oncolytic virotherapy is a novel approach for the treatment of glioblastoma multiforme (GBM) which is still a fatal disease. Pathologic features of GBM are characterized by the infiltration with microglia/macrophages and a strong interaction between immune- and glioma cells. The aim of this study was to determine the role of microglia and astrocytes for oncolytic vaccinia virus (VACV) therapy of GBM.
Methods
VACV LIVP 1.1.1 replication in C57BL/6 and \(Foxn1^{nu/nu}\) mice with and without GL261 gliomas was analyzed. Furthermore, immunohistochemical analysis of microglia and astrocytes was investigated in non-, mock-, and LIVP 1.1.1-infected orthotopic GL261 gliomas in C57BL/6 mice. In cell culture studies virus replication and virus-mediated cell death of GL261 glioma cells was examined, as well as in BV-2 microglia and IMA2.1 astrocytes with M1 or M2 phenotypes. Co-culture experiments between BV-2 and GL261 cells and apoptosis/necrosis studies were performed. Organotypic slice cultures with implanted GL261 tumor spheres were used as additional cell culture system.
Results
We discovered that orthotopic GL261 gliomas upon intracranial virus delivery did not support replication of LIVP 1.1.1, similar to VACV-infected brains without gliomas. In addition, recruitment of \(Iba1^+\) microglia and \(GFAP^+\) astrocytes to orthotopically implanted GL261 glioma sites occurred already without virus injection. GL261 cells in culture showed high virus replication, while replication in BV-2 and IMA2.1 cells was barely detectable. The reduced viral replication in BV-2 cells might be due to rapid VACV-induced apoptotic cell death. In BV-2 and IMA 2.1 cells with M1 phenotype a further reduction of virus progeny and virus-mediated cell death was detected. Application of BV-2 microglial cells with M1 phenotype onto organotypic slice cultures with implanted GL261 gliomas resulted in reduced infection of BV-2 cells, whereas GL261 cells were well infected.
Conclusion
Our results indicate that microglia and astrocytes, dependent on their activation state, may preferentially clear viral particles by immediate uptake after delivery. By acting as VACV traps they further reduce efficient virus infection of the tumor cells. These findings demonstrate that glia cells need to be taken into account for successful GBM therapy development.
We report on a nine-month-old girl who presented with persisting cough, and diminished ventilation of the left hemithorax. Viral pneumonia was suspected after Adenovirus detection by PCR, but chest X-rays showed a persistent shadowing of the left hemithorax and persistent coughing despite clinical improvement. Because of the discrepancy between clinical and radiological signs further investigations by ultrasound and CT scan were performed, which visualized an intrathroracic tumor. Histopathology confirmed diagnosis of a teratoma.
This case highlights the need for careful evaluation by the treating physicians. If the chest X-ray provides a discrepancy to the clinical findings or persistent pathologies exist, differential diagnosis should be discussed and further diagnostics be performed.
Multiple Antenatal Dexamethasone Treatment Alters Brain Vessel Differentiation in Newborn Mouse Pups
(2015)
Antenatal steroid treatment decreases morbidity and mortality in premature infants through the maturation of lung tissue, which enables sufficient breathing performance. However, clinical and animal studies have shown that repeated doses of glucocorticoids such as dexamethasone and betamethasone lead to long-term adverse effects on brain development. Therefore, we established a mouse model for antenatal dexamethasone treatment to investigate the effects of dexamethasone on brain vessel differentiation towards the blood-brain barrier (BBB) phenotype, focusing on molecular marker analysis. The major findings were that in total brains on postnatal day (PN) 4 triple antenatal dexamethasone treatment significantly downregulated the tight junction protein claudin-5, the endothelial marker Pecam-1/CD31, the glucocorticoid receptor, the NR1 subunit of the N-methyl-D-aspartate receptor, and Abc transporters (Abcb1a, Abcg2 Abcc4). Less pronounced effects were found after single antenatal dexamethasone treatment and in PN10 samples. Comparisons of total brain samples with isolated brain endothelial cells together with the stainings for Pecam-1/CD31 and claudin-5 led to the assumption that the morphology of brain vessels is affected by antenatal dexamethasone treatment at PN4. On the mRNA level markers for angiogenesis, the sonic hedgehog and the Wnt pathway were downregulated in PN4 samples, suggesting fundamental changes in brain vascularization and/or differentiation. In conclusion, we provided a first comprehensive molecular basis for the adverse effects of multiple antenatal dexamethasone treatment on brain vessel differentiation.
Emery-Dreifuss muscular dystrophy (EDMD) is a hereditary neuromuscular disorder characterized by slowly progressive muscle weakness, early contractures, and dilated cardiomyopathy. We reported an uneventful general anaesthesia using total intravenous anaesthesia (TIVA) for cardiac transplantation in a 19-year-old woman suffering from EDMD. In vitro contracture test results of two pectoralis major muscle bundles of the patient suggest that exposition to triggering agents does not induce a pathological sarcoplasmic calcium release in the lamin A/C phenotype. However, due to the lack of evidence in the literature, we would recommend TIVA for patients with EDMD if general anaesthesia is required.
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.
The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB) in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line) for proper data comparison.
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.
Stabilization of the blood-brain barrier during and after stroke can lead to less adverse outcome. For elucidation of underlying mechanisms and development of novel therapeutic strategies validated in vitro disease models of the blood-brain barrier could be very helpful. To mimic in vitro stroke conditions we have established a blood-brain barrier in vitro model based on mouse cell line cerebEND and applied oxygen/glucose deprivation (OGD). The role of astrocytes in this disease model was investigated by using cell line C6. Transwell studies pointed out that addition of astrocytes during OGD increased the barrier damage significantly in comparison to the endothelial monoculture shown by changes of transendothelial electrical resistance as well as fluorescein permeability data. Analysis on mRNA and protein levels by qPCR, western blotting and immunofluorescence microscopy of tight junction molecules claudin-3,-5,-12, occludin and ZO-1 revealed that their regulation and localisation is associated with the functional barrier breakdown. Furthermore, soluble factors of astrocytes, OGD and their combination were able to induce changes of functionality and expression of ABC-transporters Abcb1a (P-gp), Abcg2 (bcrp), and Abcc4 (mrp4). Moreover, the expression of proteases (matrixmetalloproteinases MMP-2, MMP-3, MMP-9, and t-PA) as well as of their endogenous inhibitors (TIMP-1, TIMP-3, PAI-1) was altered by astrocyte factors and OGD which resulted in significant changes of total MMP and t-PA activity. Morphological rearrangements induced by OGD and treatment with astrocyte factors were confirmed at a nanometer scale using atomic force microscopy. In conclusion, astrocytes play a major role in blood-brain barrier breakdown during OGD in vitro.
Background: Malignant hyperthermia (MH) is a rare pharmacogenetic disorder which is characterized by life-threatening metabolic crises during general anesthesia. Classical triggering substances are volatile anesthetics and succinylcholine (SCh). The molecular basis of MH is excessive release of Ca2+ in skeletal muscle principally by a mutated ryanodine receptor type 1 (RyR1). To identify factors explaining the variable phenotypic presentation and complex pathomechanism, we analyzed proven MH events in terms of clinical course, muscle contracture, genetic factors and pharmocological triggers.
Methods: In a multi-centre study including seven European MH units, patients with a history of a clinical MH episode confirmed by susceptible (MHS) or equivocal (MHE) in vitro contracture tests (IVCT) were investigated. A test result is considered to be MHE if the muscle specimens develop pathological contractures in response to only one of the two test substances, halothane or caffeine. Crises were evaluated using a clinical grading scale (CGS), results of IVCT and genetic screening. The effects of SCh and volatile anesthetics on Ca2+ release from sarcoplasmic reticulum (SR) were studied in vitro.
Results: A total of 200 patients met the inclusion criteria. Two MH crises (1%) were triggered by SCh (1 MHS, 1 MHE), 18% by volatile anesthetics and 81% by a combination of both. Patients were 70% male and 50% were younger than 12 years old. Overall, CGS was in accord with IVCT results. Crises triggered by enflurane had a significantly higher CGS compared to halothane, isoflurane and sevoflurane. Of the 200 patients, 103 carried RyR1 variants, of which 14 were novel. CGS varied depending on the location of the mutation within the RyR1 gene. In contrast to volatile anesthetics, SCh did not evoke Ca2+ release from isolated rat SR vesicles.
Conclusions: An MH event could depend on patient-related risk factors such as male gender, young age and causative RyR1 mutations as well as on the use of drugs lowering the threshold of myoplasmic Ca2+ release. SCh might act as an accelerant by promoting unspecific Ca2+ influx via the sarcolemma and indirect RyR1 activation. Most MH crises develop in response to the combined administration of SCh and volatile anesthetics.
Background: The sympathetic nervous system is considered to modulate the endotoxin-induced activation of immune cells. Here we investigate whether thoracic epidural anesthesia with its regional symapathetic blocking effect alters endotoxin-induced leukocyte-endothelium activation and interaction with subsequent endothelial injury. Methods: Sprague Dawley rats were anesthetized, cannulated and hemodynamically monitored. E. coli lipopolysaccharide (Serotype 0127: B8, 1.5 mg x kg(-1) x h(-1)) or isotonic saline (controls) was infused for 300 minutes. An epidural catheter was inserted for continuous application of lidocaine or normal saline in endotoxemic animals and saline in controls. After 300 minutes we measured catecholamine and cytokine plasma concentrations, adhesion molecule expression, leukocyte adhesion, and intestinal tissue edema. Results: In endotoxemic animals with epidural saline, LPS significantly increased the interleukin-1 beta plasma concentration (48%), the expression of endothelial adhesion molecules E-selectin (34%) and ICAM-1 (42%), and the number of adherent leukocytes (40%) with an increase in intestinal myeloperoxidase activity (26%) and tissue edema (75%) when compared to healthy controls. In endotoxemic animals with epidural infusion of lidocaine the values were similar to those in control animals, while epinephrine plasma concentration was 32% lower compared to endotoxemic animals with epidural saline. Conclusions: Thoracic epidural anesthesia attenuated the endotoxin-induced increase of IL-1 beta concentration, adhesion molecule expression and leukocyte-adhesion with subsequent endothelial injury. A potential mechanism is the reduction in the plasma concentration of epinephrine.
CXCL10 Controls Inflammatory Pain via Opioid Peptide- Containing Macrophages in Electroacupuncture
(2014)
Acupuncture is widely used for pain treatment in patients with osteoarthritis or low back pain, but molecular mechanisms remain largely enigmatic. In the early phase of inflammation neutrophilic chemokines direct opioid-containing neutrophils in the inflamed tissue and stimulate opioid peptide release and antinociception. In this study the molecular pathway and neuroimmune connections in complete Freund's adjuvant (CFA)-induced hind paw inflammation and electroacupuncture for peripheral pain control were analyzed. Free moving Wistar rats with hind paw inflammation were treated twice with electroacupuncture at GB30 (Huan Tiao - gall bladder meridian) (day 0 and 1) and analyzed for mechanical and thermal nociceptive thresholds. The cytokine profiles as well as the expression of opioid peptides were quantified in the inflamed paw. Electroacupuncture elicited long-term antinociception blocked by local injection of anti-opioid peptide antibodies (beta-endorphin, met-enkephalin, dynorphin A). The treatment altered the cytokine profile towards an anti-inflammatory pattern but augmented interferon (IFN)-gamma and the chemokine CXCL10 (IP-10: interferon gamma-inducible protein) protein and mRNA expression with concomitant increased numbers of opioid peptide-containing CXCR3+ macrophages. In rats with CFA hind paw inflammation without acupuncture repeated injection of CXCL10 triggered opioid-mediated antinociception and increase opioid-containing macrophages. Conversely, neutralization of CXCL10 time-dependently decreased electroacupuncture-induced antinociception and the number of infiltrating opioid peptide-expressing CXCR3+ macrophages. In summary, we describe a novel function of the chemokine CXCL10 - as a regulator for an increase of opioid-containing macrophages and antinociceptive mediator in inflammatory pain and as a key chemokine regulated by electroacupuncture.
Retroviral vectors are potent tools for gene delivery and various biomedical applications. To accomplish a gene transfer task successfully, retroviral vectors must effectively transduce diverse cell cultures at different phases of a cell cycle. However, very promising retroviral vectors based on the foamy viral (FV) backbone lack the capacity to efficiently transduce quiescent cells. It is hypothesized that this phenomenon might be explained as the inability of foamy viruses to form a pre-integration complex (PIC) with nuclear import activity in growth-arrested cells, which is the characteristic for lentiviruses (HIV-1). In this process, the HIV-1 central polypurine tract (cPPT) serves as a primer for plus-strand synthesis to produce a “flap” element and is believed to be crucial for the subsequent double-stranded cDNA formation of all retroviral RNA genomes. In this study, the effects of the lentiviral cPPT element on the FV transduction potential in dividing and growth-arrested (G1/S phase) adenocarcinomic human alveolar basal epithelial (A549) cells are investigated by experimental and theoretical methods. The results indicated that the HIV-1 cPPT element in a foamy viral vector background will lead to a significant reduction of the FV transduction and viral titre in growth-arrested cells due to the absence of PICs with nuclear import activity.
Background
Health-related and disease-specific quality of life (HRQoL) has been increasingly valued as relevant clinical parameter in cystic fibrosis (CF) clinical care and clinical trials. HRQoL measures should assess – among other domains – daily functioning from a patient’s perspective. However, validation studies for the most frequently used HRQoL questionnaire in CF, the Cystic Fibrosis Questionnaire (CFQ), have not included measures of physical activity or fitness. The objective of this study was, therefore, to determine the cross-sectional and longitudinal relationships between HRQoL, physical activity and fitness in patients with CF.
Methods
Baseline (n = 76) and 6-month follow-up data (n = 70) from patients with CF (age ≥12 years, FEV1 ≥35%) were analysed. Patients participated in two multi-centre exercise intervention studies with identical assessment methodology. Outcome variables included HRQoL (German revised multi-dimensional disease-specific CFQ (CFQ-R)), body composition, pulmonary function, physical activity, short-term muscle power, and aerobic fitness by peak oxygen uptake and aerobic power.
Results
Peak oxygen uptake was positively related to 7 of 13 HRQoL scales cross-sectionally (r = 0.30-0.46). Muscle power (r = 0.25-0.32) and peak aerobic power (r = 0.24-0.35) were positively related to 4 scales each, and reported physical activity to 1 scale (r = 0.29). Changes in HRQoL-scores were directly and significantly related to changes in reported activity (r = 0.35-0.39), peak aerobic power (r = 0.31-0.34), and peak oxygen uptake (r = 0.26-0.37) in 3 scales each. Established associates of HRQoL such as FEV1 or body mass index correlated positively with fewer scales (all 0.24 < r < 0.55).
Conclusions
HRQoL was associated with physical fitness, especially aerobic fitness, and to a lesser extent with reported physical activity. These findings underline the importance of physical fitness for HRQoL in CF and provide an additional rationale for exercise testing in this population.
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.
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.
Background:
Ventilation with high positive end-expiratory pressure (PEEP) can lead to hepatic dysfunction. The aim of this study was to investigate the hepatic effects of strategies using high airway pressures either in pressure-controlled ventilation (PCV) or in high-frequency oscillatory ventilation (HFOV) combined with an arteriovenous extracorporeal lung assist (ECLA).
Material/Methods:
Pietrain pigs underwent induction of lung injury by saline lavage. Ventilation was continued for 24 hours either as PCV with tidal volumes of 6 ml/kg and PEEP 3 cmH2O above the lower inflection point of the pressure-volume curve or as HFOV (≥12 Hz) with a mean tracheal airway pressure 3 cmH2O above the lower inflection point combined with arteriovenous ECLA (HFOV+ECLA). Fluids and norepinephrine stabilized the circulation. The indocyanine green plasma disappearance rate, serum bilirubin, aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, glutamate dehydrogenase, lactate dehydrogenase and creatine kinase were determined repeatedly. Finally, liver neutrophils were counted and liver cell apoptosis was assessed by terminal deoxynucleotidyl transferase nick end labeling (TUNEL).
Results:
Aspartate aminotransferase increased in the PCV group about three-fold and in the HFOV+ECLA group five-fold (p<0.001). Correspondingly, creatine kinase increased about two-fold and four-fold, respectively (p<0.001). Lactate dehydrogenase was increased in the HFOV+ECLA group (p<0.028). The number of neutrophils infiltrating the liver tissue and the apoptotic index were low.
Conclusions:
High airway pressure PCV and HFOV with ECLA in the treatment of lavage-induced lung injury in pigs did not cause liver dysfunction or damage. The detected elevation of enzymes might be of extrahepatic origin.
Background: The German-language recommendations for the management of postoperative nausea and vomiting(PONV) have been revised by an expert committee. Major aspects of this revision are presented here in the form of an evidence-based review article.
Methods: The literature was systematically reviewed with the goal of revising the existing recommendations. New evidence-based recommendations for the management of PONV were developed, approved by consensus, and graded according to the scheme of the Scottish Intercollegiate Guidelines Network (SIGN).
Results: The relevant risk factors for PONV include female sex, nonsmoker status, prior history of PONV, motion sickness, use of opioids during and after surgery, use of inhalational anesthetics and nitrous oxide, and the duration of anesthesia. PONV scoring systems provide a rough assessment of risk that can serve as the basis for a riskadapted approach. Risk-adapted prophylaxis, however, has not been shown to provide any greater benefit than fixed (combination) prophylaxis, and PONV risk scores have inherent limitations; thus, fixed prophylaxis may be advantageous. Whichever of these two approaches to manage PONV is chosen, high-risk patients must be given multimodal prophylaxis, involving both the avoidance of known risk factors and the application of multiple validated and effective antiemetic interventions. PONV should be treated as soon as it arises, to minimize patient discomfort, the risk of medical complications, and the costs involved.
Conclusion: PONV lowers patient satisfaction but is treatable. The effective, evidence-based measures of preventing and treating it should be implemented in routine practice.
Malignant hyperthermia is a rare but life-threatening complication of general anesthesia in predisposed patients usually triggered by potent inhalation anesthetics and/or the depolarizing muscle relaxant succinylcholine. The authors present a case of delayed sevoflurane-induced malignant hyperthermia in a 21-year-old male patient that was sufficiently treated by discontinuation of trigger agent application and dantrolene infusion. After surviving an MH episode diagnostic procedures are indicated to increase patient safety. In the presented case, the use of a novel minimal-invasive metabolic test with intramuscular injection of halothane and caffeine successfully confirmed MH susceptibility and hence might be an alternative for invasive in vitro contracture testing in selected cases.
The interplay of specific leukocyte subpopulations, resident cells and proalgesic mediators results in pain in inflammation. Proalgesic mediators like reactive oxygen species (ROS) and downstream products elicit pain by stimulation of transient receptor potential (TRP) channels. The contribution of leukocyte subpopulations however is less clear. Local injection of neutrophilic chemokines elicits neutrophil recruitment but no hyperalgesia in rats. In meta-analyses the monocytic chemoattractant, CCL2 (monocyte chemoattractant protein-1; MCP-1), was identified as an important factor in the pathophysiology of human and animal pain. In this study, intraplantar injection of CCL2 elicited thermal and mechanical pain in Wistar but not in Dark Agouti (DA) rats, which lack p47phox, a part of the NADPH oxidase complex. Inflammatory hyperalgesia after complete Freund's adjuvant (CFA) as well as capsaicin-induced hyperalgesia and capsaicin-induced current flow in dorsal root ganglion neurons in DA were comparable to Wistar rats. Macrophages from DA expressed lower levels of CCR2 and thereby migrated less towards CCL2 and formed limited amounts of ROS in vitro and 4-hydroxynonenal (4-HNE) in the tissue in response to CCL2 compared to Wistar rats. Local adoptive transfer of peritoneal macrophages from Wistar but not from DA rats reconstituted CCL2-triggered hyperalgesia in leukocyte-depleted DA and Wistar rats. A pharmacological stimulator of ROS production (phytol) restored CCL2-induced hyperalgesia in vivo in DA rats. In Wistar rats, CCL2-induced hyperalgesia was completely blocked by superoxide dismutase (SOD), catalase or tempol. Likewise, inhibition of NADPH oxidase by apocynin reduced CCL2-elicited hyperalgesia but not CFA-induced inflammatory hyperalgesia. In summary, we provide a link between CCL2, CCR2 expression on macrophages, NADPH oxidase, ROS and the development CCL2-triggered hyperalgesia, which is different from CFA-induced hyperalgesia. The study further supports the impact of CCL2 and ROS as potential targets in pain therapy.
Background
The epidural route is still considered the gold standard for labour analgesia, although it is not without serious consequences when incorrect placement goes unrecognized, e.g. in case of intravascular, intrathecal and subdural placements. Until now there has not been a viable alternative to epidural analgesia especially in view of the neonatal outcome and the need for respiratory support when long-acting opioids are used via the parenteral route. Pethidine and meptazinol are far from ideal having been described as providing rather sedation than analgesia, affecting the cardiotocograph (CTG), causing fetal acidosis and having active metabolites with prolonged half-lives especially in the neonate. Despite these obvious shortcomings, intramuscular and intravenously administered pethidine and comparable substances are still frequently used in delivery units.
Since the end of the 90ths remifentanil administered in a patient-controlled mode (PCA) had been reported as a useful alternative for labour analgesia in those women who either don’t want, can’t have or don’t need epidural analgesia.
Discussion
In view of the need for conversion to central neuraxial blocks and the analgesic effect remifentanil has been demonstrated to be superior to pethidine. Despite being less effective in terms of the resulting pain scores, clinical studies suggest that the satisfaction with analgesia may be comparable to that obtained with epidural analgesia. Owing to this fact, remifentanil has gained a place in modern labour analgesia in many institutions.
However, the fact that remifentanil may cause harm should not be forgotten when the use of this potent mu-agonist is considered for the use in labouring women. In the setting of one-to-one midwifery care, appropriate monitoring and providing that enough experience exists with this potent opioid and the treatment of potential complications, remifentanil PCA is a useful option in addition to epidural analgesia and other central neuraxial blocks. Already described serious consequences should remind us not refer to remifentanil PCA as a “poor man’s epidural” and to safely administer remifentanil with an appropriate indication.
Summary
Therefore, the authors conclude that economic considerations and potential cost-savings in conjunction with remifentanil PCA may not be appropriate main endpoints when studying this valuable method for labour analgesia.
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.
The blood-air barrier in the lung consists of the alveolar epithelium, the underlying capillary endothelium, their basement membranes and the interstitial space between the cell layers. Little is known about the interactions between the alveolar and the blood compartment. The aim of the present study was to gain first insights into the possible interplay between these two neighboured cell layers. We established an in vitro Transwell model of the alveolar epithelium based on human cell line H441 and investigated the influence of conditioned medium obtained from human lung endothelial cell line HPMEC-ST1.6R on the barrier properties of the H441 layers. As control for tissue specificity H441 layers were exposed to conditioned medium from human brain endothelial cell line hCMEC/D3. Addition of dexamethasone was necessary to obtain stable H441 cell layers. Moreover, dexamethasone increased expression of cell type I markers (caveolin-1, RAGE) and cell type II marker SP-B, whereas decreased the transepithelial electrical resistance (TEER) in a concentration dependent manner. Soluble factors obtained from the lung endothelial cell line increased the barrier significantly proven by TEER values and fluorescein permeability on the functional level and by the differential expression of tight junctional proteins on the molecular level. In contrast to this, soluble factors derived from brain endothelial cells weakened the barrier significantly. In conclusion, soluble factors from lung endothelial cells can strengthen the alveolar epithelium barrier in vitro, which suggests communication between endothelial and epithelial cells regulating the integrity of the blood-air barrier.
Background: Septic acute liver and intestinal failure is associated with a high mortality. We therefore investigated the influence of volume resuscitation with different crystalloid or colloid solutions on liver and intestine injury and microcirculation in septic rodents. Methods: Sepsis was induced by cecal ligation and puncture (CLP) in 77 male rats. Animals were treated with different crystalloids (NaCl 0.9% (NaCl), Ringer’s acetate (RA)) or colloids (Gelafundin 4% (Gel), 6% HES 130/0.4 (HES)). After 24 h animals were re-anesthetized and intestinal (n = 6/group) and liver microcirculation (n = 6/group) were obtained using intravital microscopy, as well as macrohemodynamic parameters were measured. Blood assays and organs were harvested to determine organ function and injury. Results: HES improved liver microcirculation, cardiac index and DO2-I, but significantly increased IL-1β, IL-6 and TNF-α levels and resulted in a mortality rate of 33%. Gel infused animals revealed significant reduction of liver and intestine microcirculation with severe side effects on coagulation (significantly increased PTT and INR, decreased haemoglobin and platelet count). Furthermore Gel showed severe hypoglycemia, acidosis and significantly increased ALT and IL-6 with a lethality of 29%. RA exhibited no derangements in liver microcirculation when compared to sham and HES. RA showed no intestinal microcirculation disturbance compared to sham, but significantly improved the number of intestinal capillaries with flow compared to HES. All RA treated animals survided and showed no severe side effects on coagulation, liver, macrohemodynamic or metabolic state. Conclusions: Gelatine 4% revealed devastated hepatic and intestinal microcirculation and severe side effects in CLP induced septic rats, whereas the balanced crystalloid solution showed stabilization of macro- and microhemodynamics with improved survival. HES improved liver microcirculation, but exhibited significantly increased pro-inflammatory cytokine levels. Crystalloid infusion revealed best results in mortality and microcirculation, when compared with colloid infusion.
Background: The present anonymous multicenter online survey was conducted to evaluate the application of regional anaesthesia techniques as well as the used local anaesthetics and adjuncts at German and Austrian university hospitals. Methods: 39 university hospitals were requested to fill in an online questionnaire, to determine the kind of regional anaesthesia and preferred drugs in urology, obstetrics and gynaecology. Results: 33 hospitals responded. No regional anaesthesia is conducted in 47% of the minor gynaecological and 44% of the urological operations; plain bupivacaine 0.5% is used in 38% and 47% respectively. In transurethral resections of the prostate and bladder no regional anaesthesia is used in 3% of the responding hospitals, whereas plain bupivacaine 0.5% is used in more than 90%. Regional anaesthesia is only used in selected major gynaecological and urological operations. On the contrary to the smaller operations, the survey revealed a large variety of used drugs and mixtures. Almost 80% prefer plain bupivacaine or ropivacaine 0.5% in spinal anaesthesia in caesarean section. Similarly to the use of drugs in major urological and gynaecological operations a wide range of drugs and adjuncts is used in epidural anaesthesia in caesarean section and spontaneous delivery. Conclusions: Our results indicate a certain agreement in short operations in spinal anaesthesia. By contrast, a large variety concerning the anaesthesiological approach in larger operations as well as in epidural analgesia in obstetrics could be revealed, the causes of which are assumed to be primarily rooted in particular departmental structures.
During stroke the blood–brain barrier (BBB) is damaged which can result in vasogenic brain edema and inflammation. The reduced blood supply leads to decreased delivery of oxygen and glucose to affected areas of the brain. Oxygen and glucose deprivation (OGD) can cause upregulation of glucose uptake of brain endothelial cells. In this letter, we investigated the influence of MK801, a non-competitive inhibitor of the NMDA-receptor, on the regulation of the glucose uptake and of the main glucose transporters glut1 and sglt1 in murine BBB cell line cerebEND during OGD. mRNA expression of glut1 was upregulated 68.7- fold after 6 h OGD, which was significantly reduced by 10 μM MK801 to 28.9-fold. Sglt1 mRNA expression decreased during OGD which was further reduced by MK801. Glucose uptake was significantly increased up to 907% after 6 h OGD and was still higher (210%) after the 20 h reoxygenation phase compared to normoxia. Ten micromolar MK801 during OGD was able to reduce upregulated glucose uptake after OGD and reoxygenation significantly. Presence of several NMDAR subunits was proven on the mRNA level in cerebEND cells. Furthermore, it was shown that NMDAR subunit NR1 was upregulated during OGD and that this was inhibitable by MK801. In conclusion, the addition of MK801 during the OGD phase reduced significantly the glucose uptake after the subsequent reoxygenation phase in brain endothelial cells.
In cats anesthetized with alpha-chloralose, extracellular recordings were made from fine afferent units belonging to the medial articular nerve (MAN) of the knee joint. The excitatory and sensitizing effects on articular afferents of serotonin (5-HT) applied intra-arterially close to the joint were examined. The joints were either normal or an experimental arthritis had been induced some hours before the recording session. Bolus injections of 1.35-135 p,g 5-HT excited about 43% of group 111 (CV: 2.5-20 m/sec) and 73% of group IV units (CV: < 2.5 mjsec) from normal joints. The latency was usually between 10 and 30 sec, and the duration and size of the responses were dose-dependent. Fast group 111 units (CV: > 16 mjsec) and group li units (CV: > 20 m/sec) were never excited by 5-HT. Repetitiveadministration led to pronounced tachyphylaxis of the 5-HT response. Inflammation induced an enhanced sensitivity of group III articular afferent units to close intra-arterial application of 5-HT. In particular the total duration of each response was considerably prolonged (4-10 min against 1-2 min under normal conditions). At the same time the tachyphylaxis seen under normal conditions was gteatly reduced. In contrast, group IV articular afferent units did not become sensitized to 5-HT in the course of inflammation. In normal joints 5-HT did not sensitize fineafferent units for movement-induced responses. However, after inflammation, a distinct sensitization to such movements by 5-HT application could be observed bothin group 111 and group IV fiber ranges. The sensitization had a short time course not exceeding 7 min. The tonic component of the movement-induced response was more enhanced than the phasic one. The bolus application of 5-HT led to temporary vasoconstriction of the knee joint vessels. This vasoconstriction was especially pronounced in inflamed joints and impeded the access of subsequently applied substances to the terminal regions of the afferent units under observation. lt is concluded that the present results support the notion that 5-HT may participate in the mediation of pain from inflamed tissue such as an arthritic joint by exciting and sensitizing fine afferent units. During inflammation group 111 units are particularly sensitive to 5-HT and, thus, may carry the bulk of the 5-HT-induced nociceptive messages.