Early elevation in plasma high-sensitivity troponin T and morbidity after elective noncardiac surgery: prospective multicentre observational cohort study.

BACKGROUND: Elevated high-sensitivity troponin (hsTnT) after noncardiac surgery is associated with higher mortality, but the temporal relationship between early elevated troponin and the later development of noncardiac morbidity remains unclear. METHODS: Prospective observational study of patients aged ≥45 yr undergoing major noncardiac surgery at four UK hospitals (two masked to hsTnT). The exposure of interest was early elevated troponin, as defined by hsTnT >99th centile (≥15 ng L-1) within 24 h after surgery. The primary outcome was morbidity 72 h after surgery, defined by the Postoperative Morbidity Survey (POMS). Secondary outcomes were time to become morbidity-free and Clavien-Dindo ≥grade 3 complications. RESULTS: Early elevated troponin (median 21 ng L-1 [16-32]) occurred in 992 of 4335 (22.9%) patients undergoing elective noncardiac surgery (mean [standard deviation, sd] age, 65 [11] yr; 2385 [54.9%] male). Noncardiac morbidity was more frequent in 494/992 (49.8%) patients with early elevated troponin compared with 1127/3343 (33.7%) patients with hsTnT <99th centile (odds ratio [OR]=1.95; 95% confidence interval [CI], 1.69-2.25). Patients with early elevated troponin had a higher risk of proven/suspected infectious morbidity (OR=1.54; 95% CI, 1.24-1.91) and critical care utilisation (OR=2.05; 95% CI, 1.73-2.43). Clavien-Dindo ≥grade 3 complications occurred in 167/992 (16.8%) patients with early elevated troponin, compared with 319/3343 (9.5%) patients with hsTnT <99th centile (OR=1.78; 95% CI, 1.48-2.14). Absence of early elevated troponin was associated with morbidity-free recovery (OR=0.44; 95% CI, 0.39-0.51). CONCLUSIONS: Early elevated troponin within 24 h of elective noncardiac surgery precedes the subsequent development of noncardiac organ dysfunction and may help stratify levels of postoperative care in real time.

Troponin T monitoring to detect myocardial injury after noncardiac surgery: a cost-consequence analysis.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is a mostly asymptomatic condition that is strongly associated with 30-day mortality; however, it remains mostly undetected without systematic troponin T monitoring. We evaluated the cost and consequences of postoperative troponin T monitoring to detect MINS. METHODS: We conducted a model-based cost-consequence analysis to compare the impact of routine troponin T monitoring versus standard care (troponin T measurement triggered by ischemic symptoms) on the incidence of MINS detection. Model inputs were based on Canadian patients enrolled in the Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) study, which enrolled patients aged 45 years or older undergoing inpatient noncardiac surgery. We conducted probability analyses with 10 000 iterations and extensive sensitivity analyses. RESULTS: The data were based on 6021 patients (48% men, mean age 65 [standard deviation 12] yr). The 30-day mortality rate for MINS was 9.6%. We determined the incremental cost to avoid missing a MINS event as $1632 (2015 Canadian dollars). The cost-effectiveness of troponin monitoring was higher in patient subgroups at higher risk for MINS, e.g., those aged 65 years or more, or with a history of atherosclerosis or diabetes ($1309). CONCLUSION: The costs associated with a troponin T monitoring program to detect MINS were moderate. Based on the estimated incremental cost per health gain, implementation of postoperative troponin T monitoring seems appealing, particularly in patients at high risk for MINS.

CONTEXTE: Les lésions myocardiques après chirurgie non cardiaque (CNC) sont majoritairement asymptomatiques et fortement associées au risque de mortalité dans les 30 jours; toutefois, dans la plupart des cas, elles ne sont pas détectées en l'absence d'une surveillance systématique de la troponine T. Nous avons évalué les coûts et les conséquences d'une telle surveillance pour détecter les lésions myocardiques après CNC. MÉTHODES: Nous avons mené une analyse coût-conséquence modélisée pour comparer la surveillance systématique de la troponine T aux soins habituels seuls (mesure de la troponine T seulement s'il y a présence de symptômes d'ischémie) sur la fréquence de détection de lésions myocardiques après CNC. Les données ayant servi à l'analyse provenaient des patients canadiens ayant participé à l'étude de cohorte VISION, qui visait à évaluer les complications vasculaires chez les patients de 45 ans et plus ayant subi une CNC. Nous avons mené des analyses de probabilité avec 10  000 itérations et des analyses de sensibilité approfondies. RÉSULTATS: Les données portaient sur 6021 patients (48 % du sexe masculin; âge moyen de 65 ans [écart-type de 12 ans]). Le taux de mortalité dans les 30 jours associé à une lésion myocardique après CNC était de 9,6 %. Nous avons déterminé que le coût marginal de la détection de la présence d'une lésion par surveillance de la troponine T était de 1632 $ (dollars canadiens en 2015). Le rapport coût-efficacité était plus bas pour les sous-groupes de patients à risque élevé de lésion myocardique après CNC, comme les patients de 65 ans et plus ou ceux ayant des antécédents d'athérosclérose ou de diabète (1309 $), que pour leurs pairs. CONCLUSION: Les coûts associés à un programme de surveillance de la troponine T pour détecter les lésions myocardiques après CNC étaient modérés. Le coût marginal estimé par gain de santé indique que la mise en œuvre de ce type de programme pourrait être une option intéressante, surtout pour les patients à risque élevé de lésion myocardique après CNC.

Lipopolysaccharide induces a downregulation of adiponectin receptors in-vitro and in-vivo.

Background. Adipose tissue contributes to the inflammatory response through production of cytokines, recruitment of macrophages and modulation of the adiponectin system. Previous studies have identified a down-regulation of adiponectin in pathologies characterised by acute (sepsis and endotoxaemia) and chronic inflammation (obesity and type-II diabetes mellitus). In this study, we investigated the hypothesis that LPS would reduce adiponectin receptor expression in a murine model of endotoxaemia and in adipoocyte and myocyte cell cultures. Methods. 25 mg/kg LPS was injected intra-peritoneally into C57BL/6J mice, equivalent volumes of normal saline were used in control animals. Mice were killed at 4 or 24 h post injection and tissues harvested. Murine adipocytes (3T3-L1) and myocytes (C2C12) were grown in standard culture, treated with LPS (0.1 µg/ml-10 µg/ml) and harvested at 4 and 24 h. RNA was extracted and qPCR was conducted according to standard protocols and relative expression was calculated. Results. After LPS treatment there was a significant reduction after 4 h in gene expression of adipo R1 in muscle and peri-renal fat and of adipo R2 in liver, peri-renal fat and abdominal wall subcutaneous fat. After 24 h, significant reductions were limited to muscle. Cell culture extracts showed varied changes with reduction in adiponectin and adipo R2 gene expression only in adipocytes. Conclusions. LPS reduced adiponectin receptor gene expression in several tissues including adipocytes. This reflects a down-regulation of this anti-inflammatory and insulin-sensitising pathway in response to LPS. The trend towards base line after 24 h in tissue depots may reflect counter-regulatory mechanisms. Adiponectin receptor regulation differs in the tissues investigated.

Longstanding complex regional pain syndrome is associated with activating autoantibodies against alpha-1a adrenoceptors.

Complex regional pain syndrome (CRPS) is a limb-confined posttraumatic pain syndrome with sympathetic features. The cause is unknown, but the results of a randomized crossover trial on low-dose intravenous immunoglobulins (IVIG) treatment point to a possible autoimmune mechanism. We tested purified serum immunoglobulin G (IgG) from patients with longstanding CRPS for evidence of antibodies interacting with autonomic receptors on adult primary cardiomyocytes, comparing with control IgG from healthy and diseased controls, and related the results to the clinical response to treatment with low-dose IVIG. We simultaneously recorded both single-cell contractions and intracellular calcium handling in an electrical field. Ten of 18 CRPS preparations and only 1/57 control preparations (P<0.0001) increased the sensitivity of the myocytes to the electric field, and this effect was abrogated by preincubation with α-1a receptor blockers. By contrast, effects on baseline calcium were blocked by preincubation with atropine. Interestingly, serum-IgG preparations from all 4 CRPS patients who had responded to low-dose IVIG with meaningful pain relief were effective in these assays, although 4/8 of the nonresponders were also active. To see if there were antibodies to the α-1a receptor, CRPS-IgG was applied to α-1a receptor-transfected rat-1 fibroblast cells. The CRPS serum IgG induced calcium flux, and fluorescence-activated cell sorting showed that there was serum IgG binding to the cells. The results suggest that patients with longstanding CRPS have serum antibodies to α-1a receptors, and that measurement of these antibodies may be useful in the diagnosis and management of the patients.

A combination of topical antiseptics for the treatment of sore throat blocks voltage-gated neuronal sodium channels.

Amylmetacresol and dichloro-benzylalcohol are ingredients of lozenges used for the treatment of sore throat. In a former in vitro study, a local anaesthetic-like effect of these substances has been described. Since amylmetacresol and dichloro-benzylalcohol are co-administered in over-the-counter lozenges, the intention of this study is to evaluate the in vitro effects of the combination of these compounds on the voltage-gated sodium channel. We analysed the block of inward sodium currents induced by the combination of amylmetacresol, dichloro-benzylalcohol and the local anaesthetic lidocaine. Tonic and use-dependent block and effects on the inactivated channel state of the neuronal sodium channel were examined. Therefore, the α-subunit of the voltage-gated NaV1.2 sodium channel was heterologously expressed in HEK 293 cells in vitro. Inward sodium currents were investigated in the whole-cell configuration of the patch-clamp technique. The combination of amylmetacresol and dichloro-benzylalcohol and the combination of amylmetacresol and lidocaine induced a block of resting and inactivated sodium channels both displaying a pronounced block at the inactivated channel state. In addition, the combination of all three compounds also resulted in a voltage-dependent block of inward sodium currents. While use-dependent block by co-application of amylmetacresol and dichloro-benzylalcohol was moderate (<20 %), lidocaine and amylmetacresol induced a robust use-dependent block (up to 50 %). This study demonstrates local anaesthetic-like effects of a combination of amylmetacresol and dichloro-benzylalcohol as established ingredients of lozenges. In the presence of amylmetacresol, dichloro-benzylalcohol and lidocaine, a prominent block of inward sodium currents is apparent.

Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) was defined as prognostically relevant myocardial injury due to ischemia that occurs during or within 30 days after noncardiac surgery. The study's four objectives were to determine the diagnostic criteria, characteristics, predictors, and 30-day outcomes of MINS. METHODS: In this international, prospective cohort study of 15,065 patients aged 45 yr or older who underwent in-patient noncardiac surgery, troponin T was measured during the first 3 postoperative days. Patients with a troponin T level of 0.04 ng/ml or greater (elevated "abnormal" laboratory threshold) were assessed for ischemic features (i.e., ischemic symptoms and electrocardiography findings). Patients adjudicated as having a nonischemic troponin elevation (e.g., sepsis) were excluded. To establish diagnostic criteria for MINS, the authors used Cox regression analyses in which the dependent variable was 30-day mortality (260 deaths) and independent variables included preoperative variables, perioperative complications, and potential MINS diagnostic criteria. RESULTS: An elevated troponin after noncardiac surgery, irrespective of the presence of an ischemic feature, independently predicted 30-day mortality. Therefore, the authors' diagnostic criterion for MINS was a peak troponin T level of 0.03 ng/ml or greater judged due to myocardial ischemia. MINS was an independent predictor of 30-day mortality (adjusted hazard ratio, 3.87; 95% CI, 2.96-5.08) and had the highest population-attributable risk (34.0%, 95% CI, 26.6-41.5) of the perioperative complications. Twelve hundred patients (8.0%) suffered MINS, and 58.2% of these patients would not have fulfilled the universal definition of myocardial infarction. Only 15.8% of patients with MINS experienced an ischemic symptom. CONCLUSION: Among adults undergoing noncardiac surgery, MINS is common and associated with substantial mortality.

Circulating anti-inflammatory adipokines High Molecular Weight Adiponectin and Zinc-α2-glycoprotein (ZAG) are inhibited in early sepsis, but increase with clinical recovery: a pilot study.

BACKGROUND: Adipose tissue has been identified as an endocrine organ secreting adipokines involved in metabolic and inflammatory pathways. Adiponectin, an anti-inflammatory adipokine, is reduced in sepsis. High Molecular Weight (HMW) adiponectin, the biologically most relevant molecule, has been investigated very little in human sepsis. Zinc-alpha2-glycoprotein (ZAG) is a novel adipokine and its expression in adipose tissue is positively correlated with adiponectin expression. It is not yet known whether ZAG has a role in sepsis. In this study we assessed levels of HMW adiponectin and ZAG during different stages of sepsis. METHODS: A prospective observational pilot study was carried out on 21 septic patients. Serum samples were taken on day 1 and 2 post ICU admission and on day of discharge. Samples were analysed for total and HMW adiponectin, HMW/total adiponectin ratio, and ZAG. Results were correlated with clinical and metabolic data. RESULTS: There were no differences in total adiponectin, HMW adiponectin and ZAG plasma concentrations between day 1 (admission) and day 2 of the sepsis episode. Compared to admission, a significant increase in total and HMW adiponectin and ZAG was observed on the day of discharge when clinical improvement had been achieved. There was also an increase in the HMW/total adiponectin ratio at that time. CONCLUSIONS: Our data demonstrate an increase in both HMW adiponectin and total adiponectin in patients who had clinically recovered from sepsis. The increase in HMW/total adiponectin ratio with improvement of the clinical condition suggests that HMW adiponectin may have a greater role in the inflammatory process and insulin resistance seen in sepsis. In this pilot study, we have also demonstrated a significant increase in ZAG in critically ill patients temporally related to recovery from sepsis.

4-Chloropropofol enhances chloride currents in human hyperekplexic and artificial mutated glycine receptors.

BACKGROUND: The mammalian neurological disorder hereditary hyperekplexia can be attributed to various mutations of strychnine sensitive glycine receptors. The clinical symptoms of "startle disease" predominantly occur in the newborn leading to convulsive hypertonia and an exaggerated startle response to unexpected mild stimuli. Amongst others, point mutations R271Q and R271L in the α1-subunit of strychnine sensitive glycine receptors show reduced glycine sensitivity and cause the clinical symptoms of hyperekplexia.Halogenation has been shown to be a crucial structural determinant for the potency of a phenolic compound to positively modulate glycine receptor function.The aim of this in vitro study was to characterize the effects of 4-chloropropofol (4-chloro-2,6-dimethylphenol) at four glycine receptor mutations. METHODS: Glycine receptor subunits were expressed in HEK 293 cells and experiments were performed using the whole-cell patch-clamp technique. RESULTS: 4-chloropropofol exerted a positive allosteric modulatory effect in a low sub-nanomolar concentration range at the wild type receptor (EC50 value of 0.08 ± 0.02 nM) and in a micromolar concentration range at the mutations (1.3 ± 0.6 µM, 0.1 ± 0.2 µM, 6.0 ± 2.3 µM and 55 ± 28 µM for R271Q, L, K and S267I, respectively). CONCLUSIONS: 4-chloropropofol might be an effective compound for the activation of mutated glycine receptors in experimental models of startle disease.

Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery.

CONTEXT: Of the 200 million adults worldwide who undergo noncardiac surgery each year, more than 1 million will die within 30 days. OBJECTIVE: To determine the relationship between the peak fourth-generation troponin T (TnT) measurement in the first 3 days after noncardiac surgery and 30-day mortality. DESIGN, SETTING, AND PARTICIPANTS: A prospective, international cohort study that enrolled patients from August 6, 2007, to January 11, 2011. Eligible patients were aged 45 years and older and required at least an overnight hospital admission after having noncardiac surgery. MAIN OUTCOME MEASURES: Patients' TnT levels were measured 6 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We undertook Cox regression analysis in which the dependent variable was mortality until 30 days after surgery, and the independent variables included 24 preoperative variables. We repeated this analysis, adding the peak TnT measurement during the first 3 postoperative days as an independent variable and used a minimum P value approach to determine if there were TnT thresholds that independently altered patients' risk of death. RESULTS: A total of 15,133 patients were included in this study. The 30-day mortality rate was 1.9% (95% CI, 1.7%-2.1%). Multivariable analysis demonstrated that peak TnT values of at least 0.02 ng/mL, occurring in 11.6% of patients, were associated with higher 30-day mortality compared with the reference group (peak TnT ≤ 0.01 ng/mL): peak TnT of 0.02 ng/mL (adjusted hazard ratio [aHR], 2.41; 95% CI, 1.33-3.77); 0.03 to 0.29 ng/mL (aHR, 5.00; 95% CI, 3.72-6.76); and 0.30 ng/mL or greater (aHR, 10.48; 95% CI, 6.25-16.62). Patients with a peak TnT value of 0.01 ng/mL or less, 0.02, 0.03-0.29, and 0.30 or greater had 30-day mortality rates of 1.0%, 4.0%, 9.3%, and 16.9%, respectively. Peak TnT measurement added incremental prognostic value to discriminate those likely to die within 30 days for the model with peak TnT measurement vs without (C index = 0.85 vs 0.81; difference, 0.4; 95% CI, 0.2-0.5; P < .001 for difference between C index values). The net reclassification improvement with TnT was 25.0% (P < .001). CONCLUSION: Among patients undergoing noncardiac surgery, the peak postoperative TnT measurement during the first 3 days after surgery was significantly associated with 30-day mortality.

Defective polysialylation and sialylation induce opposite effects on gating of the skeletal Na+ channel NaV1.4 in Chinese hamster ovary cells.

Polysialic acid (polySia) is a large, negatively charged homopolymer of 2,8-linked N-acetylneuraminic acid residues resulting from remodeling and extension of protein-bound sialic acid (Sia) residues and seems to have a key role in regulating neural cell development and function. The aim of this study was to explore and compare the effects of polySia and sialylation on gating of voltage-gated sodium channels. The skeletal muscle α-subunit NaV1.4 was transiently expressed in wild-type Chinese hamster ovary (CHO) cells or in mutant CHO cells with deficits in their capacity to produce sialylated or polysialylated membrane components. Expression in both mutant cell lines resulted in larger peak current amplitudes as compared to wild-type CHO cells. Loss of Sia and polySia also resulted in significant shifts of voltage-dependent activation and steady-state inactivation, however, in opposite directions. Furthermore, only the loss of Sia had a significant effect on recovery from fast inactivation. Our data demonstrate for the first time that gating of voltage-gated sodium channels seems to be differentially regulated by polySia and Sia.

Paracetamol fails to positively modulate and directly activate chloride currents in human α1-glycine receptors.

Paracetamol (acetaminophen) is a widely used antipyretic and analgesic drug for mild or moderate pain states. As the primary site of action of paracetamol is still the subject of ongoing discussion, the focus of this study is the investigation of a potential mechanism which might contribute to its beneficial effects in the therapy of pain. Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. In this study we investigated the interaction of paracetamol with strychnine-sensitive α(1)-glycine receptors (α(1)-GlyR). α(1)-GlyR subunits transiently expressed in HEK-293 cells were studied using the whole-cell patch-clamp technique and a piezo-controlled liquid filament fast application system. Paracetamol fails to show a positive allosteric modulatory effect in low nano- to micromolar concentrations and lacks direct activation in micromolar concentrations at the α(1)-GlyR. Consequently, the analgesic actions of paracetamol leading to pain relief appear to be mediated via other mechanisms, but not via activation of spinal glycinergic pathways.

Lack of positive allosteric modulation of mutated alpha(1)S267I glycine receptors by cannabinoids.

Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. Ajulemic acid and HU210 are non-psychotropic, synthetic cannabinoids. Cannabidiol is a non-psychotropic plant constituent of cannabis sativa. There are hints that non-cannabinoid receptor mechanisms of these cannabinoids might be mediated via glycine receptors. In this study, we investigated the impact of the amino acid residue serine at position 267 on the glycine-modulatory effects of ajulemic acid, cannabidiol and HU210. Mutated alpha(1)S267I glycine receptors transiently expressed in HEK293 cells were studied by utilising the whole-cell clamp technique. The mutation of the alpha(1) subunit TM2 serine residue to isoleucine abolished the co-activation and the direct activation of the glycine receptor by the investigated cannabinoids. The nature of the TM2 (267) residue of the glycine alpha(1) subunit is crucial for the glycine-modulatory effect of ajulemic acid, cannabidiol and HU210. An investigation of the impact of such mutations on the in vivo interaction of cannabinoids with glycine receptors should permit a better understanding of the molecular determinants of action of cannabinoids.

Topical antiseptics for the treatment of sore throat block voltage-gated neuronal sodium channels in a local anaesthetic-like manner.

Lozenges for the treatment of sore throat provide relief of discomfort in cases of oral inflammation. This effect has not been fully explained so far. Here, we have examined the proposition that key components of pharmaceutical preparations for the treatment of sore throat which are routinely regarded antiseptics might have sodium channel-blocking, i.e. local anaesthetic-like effects. We investigated the effects of hexylresorcinol, amylmetacresol and dichloro-benzylalcohol on voltage-operated neuronal (Na(V)1.2) sodium channels heterologously expressed in HEK 293 cells in vitro. Hexylresorcinol, amylmetacresol and dichloro-benzylalcohol reversibly blocked depolarisation-induced whole-cell sodium inward currents. The half-maximum blocking concentrations (EC(50)) at -150 mV were 23.1, 53.6 and 661.6 microM, respectively. Block induced by hexylresorcinol and amylmetacresol was increased at depolarised potentials and use-dependent during trains of depolarisations applied at high frequency (100 Hz) indicating that both drugs bind more tightly to inactivated conformations of the channel. Estimates for the inactivated state affinity were 1.88 and 35 microM for hexylresorcinol and amylmetacresol, respectively. Hexylresorcinol and amylmetacresol are 10-20 fold more potent than the local anaesthetic lidocaine in blocking sodium inward current. Both drugs show an increased effect at depolarised membrane potentials or in conditions of high-frequency discharges.

Modulation of glycine receptor function by the synthetic cannabinoid HU210.

Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. HU210 is a non-psychotropic, synthetic cannabinoid. As we hypothesized that non-CB receptor mechanisms of HU210 might contribute to its anti-inflammatory and anti-nociceptive effects we investigated the interaction of HU210 with strychnine-sensitive alpha(1 )glycine receptors by using the whole-cell patch clamp technique. HU210 showed a positive allosteric modulating effect in a low micromolar concentration range (EC(50): 5.1 +/- 2.6 micromol/l). Direct activation of glycine receptors was observed at higher concentrations above 100 micromol/l (EC(50): 188.7 +/- 46.2 micromol/l). These in vitro results suggest that strychnine-sensitive glycine receptors may be a target for HU210 mediating some of its anti-inflammatory and anti-nociceptive properties.

The nonpsychotropic cannabinoid cannabidiol modulates and directly activates alpha-1 and alpha-1-Beta glycine receptor function.

Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. Cannabidiol is a nonpsychotropic plant constituent of Cannabis sativa. As we hypothesized that non-CB receptor mechanisms of cannabidiol might contribute to its anti-inflammatory and neuroprotective effects, we investigated the interaction of cannabidiol with strychnine-sensitive alpha(1 )and alpha(1)beta glycine receptors by using the whole-cell patch clamp technique. Cannabidiol showed a positive allosteric modulating effect in a low micromolar concentration range (EC(50) values: alpha(1) = 12.3 +/- 3.8 micromol/l and alpha(1)beta = 18.1 +/- 6.2 micromol/l). Direct activation of glycine receptors was observed at higher concentrations above 100 micromol/l (EC(50) values: alpha(1) = 132.4 +/- 12.3 micromol/l and alpha(1)beta = 144.3 +/- 22.7 micromol/l). These in vitro results suggest that strychnine-sensitive glycine receptors may be a target for cannabidiol mediating some of its anti-inflammatory and neuroprotective properties.

Retention and transferability of team resource management skills in anaesthetic emergencies: the long-term impact of a high-fidelity simulation-based course.

BACKGROUND AND OBJECTIVE: In 2005, we developed and implemented the Emergency Anaesthetic Simulated Experience course at the Cheshire and Merseyside Simulation Centre.Emergency Anaesthetic Simulated Experience aims to teach clinical and team resource management skills to junior trainees in anaesthesia. Here we present 'proof-of-concept' in terms of long-term retention and transferability of acquired skills into subsequent clinical practice. METHODS: An electronic questionnaire sent to 73 trainees, 9-20 months after the course, invited open-ended responses, addressing four areas; namely, real-life encounters with the same scenario as on the course, approach to real-life anaesthetic emergencies in general, approach to real-life routine anaesthesia and need to attend similar courses in the future, with their underlying reasons. RESULTS: Qualitative analysis of the descriptive responses showed that the lessons learnt in the context of simulated emergencies were applied by candidates themselves to real-life emergencies in general and to routine practice. CONCLUSION: Team resource management skills learnt in a single educational intervention, based on simulated anaesthetic emergencies, are retained over the long term, translated into clinical practice and are transferable across the breadth of clinical activities.

Positive allosteric modulatory effects of ajulemic acid at strychnine-sensitive glycine alpha1- and alpha1beta-receptors.

The synthetic cannabinoid ajulemic acid (CT-3) is a potent cannabinoid receptor agonist which was found to reduce pain scores in neuropathic pain patients in the absence of cannabis-like psychotropic adverse effects. The reduced psychotropic activity of ajulemic acid has been attributed to a greater contribution of peripheral CB receptors to its mechanism of action as well as to non-CB receptor mechanisms. Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. As we hypothesised that additional non-CB receptor mechanisms of ajulemic acid might contribute to its effect in neuropathic pain, we investigated the interaction of ajulemic acid with strychnine-sensitive alpha(1)- and alpha(1)beta-glycine receptors by using the whole-cell patch clamp technique. Ajulemic acid showed a positive allosteric modulating effect in a concentration range which can be considered close to clinically relevant concentrations (EC(50) values: alpha(1) = 9.7 +/- 2.6 microM and alpha(1)beta = 12.4 +/- 3.4 microM). Direct activation of glycine receptors was observed at higher concentrations above 100 microM (EC(50) values: alpha(1) = 140.9 +/- 21.5 microM and alpha(1)beta = 154.3 +/- 32.1 microM). These in vitro results demonstrate that ajulemic acid modulates strychnine-sensitive glycine receptors in clinically relevant concentrations.

Endotoxaemia leads to major increases in inflammatory adipokine gene expression in white adipose tissue of mice.

The proposition that white adipose tissue is involved in the inflammatory response and metabolic dysregulation of endotoxaemia has been examined. Mice were injected with lipopolysaccharide (LPS; 25 mg/kg) and epididymal, perirenal and subcutaneous adipose tissue removed 4 or 24 h later. The expression of genes encoding key inflammation-related adipokines was measured by real-time polymerase chain reaction. At 24 h after the administration of LPS, there was no change in leptin mRNA level, and adiponectin mRNA fell. However, major increases in TNFalpha, MCP-1 (up to 40-fold) and IL-6 (up to 250-fold) mRNA levels were evident; a substantial elevation in these mRNAs occurred by 4 h, and adipose tissue IL-6 protein also increased (three- to eightfold). At 24 h, the responses in the subcutaneous depot were much lower than in epididymal and perirenal adipose tissue, but at 4 h, the subcutaneous tissue showed major increases in IL-6, MCP-1 and TNFalpha gene expression. In contrast to the inflammatory adipokines, the mRNA level of two macrophage markers, F4/80 and MAC-1, was unaltered in adipose tissue during endotoxaemia. Expression of the hypoxia-sensitive transcription factor, HIF-1alpha, gene was increased at both 4 and 24 h, and HIF-1alpha protein was elevated at 4 h, suggesting that the tissue was hypoxic. It is concluded that white adipose tissue may play an important role in the production of inflammatory mediators in endotoxaemia.

The non-anaesthetic propofol analogue 2,6-di-tert-butylphenol fails to modulate GABA(A) receptor function.

Modulation of inhibitory synaptic transmission within the central nervous system contributes considerably to the anaesthetic effects of propofol and its analogues in vivo. We have studied the effects of the non-anaesthetic propofol analogue 2,6-di-tert-butylphenol on rat alpha(1)beta(2)gamma(2) GABA(A) receptors expressed in a mammalian expression system (HEK 293 cells) using the whole-cell patch clamp technique. Our experiments showed that 2,6-di-tert-butylphenol completely lacks co-activation and direct activation of the inhibitory GABA(A) receptor. Our results support the assumption that modulation of inhibitory GABA(A) receptor function is responsible for the anaesthetic effects of propofol in vivo.