The Actin Binding Domain of βI-Spectrin Regulates the Morphological and Functional Dynamics of Dendritic Spines

Actin microfilaments regulate the size, shape and mobility of dendritic spines and are in turn regulated by actin binding proteins and small GTPases. The βI isoform of spectrin, a protein that links the actin cytoskeleton to membrane proteins, is present in spines. To understand its function, we expressed its actin-binding domain (ABD) in CA1 pyramidal neurons in hippocampal slice cultures. The ABD of βI-spectrin bundled actin in principal dendrites and was concentrated in dendritic spines, where it significantly increased the size of the spine head. These effects were not observed after expression of homologous ABDs of utrophin, dystrophin, and α-actinin. Treatment of slice cultures with latrunculin-B significantly decreased spine head size and decreased actin-GFP fluorescence in cells expressing the ABD of α-actinin, but not the ABD of βI-spectrin, suggesting that its presence inhibits actin depolymerization. We also observed an increase in the area of GFP-tagged PSD-95 in the spine head and an increase in the amplitude of mEPSCs at spines expressing the ABD of βI-spectrin. The effects of the βI-spectrin ABD on spine size and mEPSC amplitude were mimicked by expressing wild-type Rac3, a small GTPase that co-immunoprecipitates specifically with βI-spectrin in extracts of cultured cortical neurons. Spine size was normal in cells co-expressing a dominant negative Rac3 construct with the βI-spectrin ABD. We suggest that βI-spectrin is a synaptic protein that can modulate both the morphological and functional dynamics of dendritic spines, perhaps via interaction with actin and Rac3

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Ultrashort pulse laser ablation for depth profiling of bacterial biofilms

Sample ablation by pulsed lasers is one option for removing material from a sample surface for in situ depth profiling during imaging mass spectrometry, but ablation is often limited by laser-induced damage of the remaining material. A preliminary evaluation was performed of sub-100-fs, 800 nm pulsed laser ablation for depth profiling of bacterial biofilms grown on glass by the drip flow method. Electron and optical microscopy were combined with laser desorption vacuum ultraviolet postionization mass spectrometry to analyze biofilms before and after ablation. Ultrashort laser pulses can ablate [Formula: see text] thick sections of bacterial biofilms, leaving behind a layer of lysed cells. However, mass spectra from intact and ablated biofilms doped with antibiotic are almost identical, indicating little chemical degradation by ablation. These results are consistent with prior observations from laser surgery and support the use of ultrashort pulse laser ablation for minimally disruptive depth profiling of bacterial biofilms and intact biological samples

Decreased placental and transcellular permeation of cefuroxime in pregnant women with diabetes

Background: The present study investigated the transcellular and placental permeation of cefuroxime, an antibiotic used in cesarean sections, in pregnant women with diabetes and hypertension. Methods: Fifty-three women scheduled for cesarean section were divided into three groups: healthy women (n=18), women with arterial hypertension (n=21), and women with gestational diabetes (n=14). All women received 1.5g, i.v., cefuroxime. Cefuroxime concentrations were measured in maternal venous plasma before, during, and after delivery, as well as in fetal umbilical cord vein and artery plasma during delivery. The effects of diabetes and hypertension on cefuroxime placental-permeation were assessed by the fetomaternal plasma concentration ratios. Pharmacokinetic non-compartmental model analyses were performed and results were compared using anova. Results: Fetomaternal drug concentration ratios were lower in the diabetic group than in the hypertensive and control groups. There were no significant differences in umbilical arterial:venous plasma drug concentration ratios in the diabetic and hypertensive groups compared with the control group. Apparent volume of distribution and clearance were significantly lower in the diabetic group compared with the control and hypertensive groups. Conclusions: Diabetes led to decreased placental transfer of cefuroxime, as well as volume of distribution and clearance, but did not affect other pharmacokinetic parameters. Hypertension had no significant effect on the permeation of cefuroxime or on its pharmacokinetics. Prophylactic concentrations of cefuroxime were reached in all groups, but the dosing time of cefuroxime should not be less than 30min or greater than 2h prior to delivery

Rac controls PIP5K localisation and PtdIns(4,5)P2 synthesis, which modulates vinculin localisation and neurite dynamics

In N1E-115 cells, neurite retraction induced by neurite remodelling factors such as lysophosphatidic acid, sphingosine 1-phosphate and semaphorin 3A require the activity of phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks). PIP5Ks synthesise the phosphoinositide lipid second messenger phosphatidylinositol(4,5) bisphosphate [PtdIns(4,5)P-2], and overexpression of active PIP5K is sufficient to induce neurite retraction in both N1E-115 cells and cerebellar granule neurones. However, how PIP5Ks are regulated or how they induce neurite retraction is not well defined. Here, we show that neurite retraction induced by PIP5K beta is dependent on its interaction with the low molecular weight G protein Rac. We identified the interaction site between PIP5K beta and Rac1 and generated a point mutant of PIP5K beta that no longer interacts with endogenous Rac. Using this mutant, we show that Rac controls the plasma membrane localisation of PIP5K beta and thereby the localised synthesis of PtdIns(4,5)P-2 required to induce neurite retraction. Mutation of this residue in other PIP5K isoforms also attenuates their ability to induce neurite retraction and to localise at the membrane. To clarify how increased levels of PtdIns(4,5)P-2 induce neurite retraction, we show that mutants of vinculin that are unable to interact with PtdIns(4,5)P-2, attenuate PIP5K- and LPA-induced neurite retraction. Our findings support a role for PtdIns(4,5)P-2 synthesis in the regulation of vinculin localisation at focal complexes and ultimately in the regulation of neurite dynamic

Using simulated experience to make sense of big data

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Simulated experience can help companies communicate data analysis results to decision makers. Analysts' conclusions have been found to be different from what decision makers understand. Meanwhile, complex statistical information have been found to be misleading at times

Vagus Nerve Stimulation for the Treatment of Heart Failure The INOVATE-HF Trial

BACKGROUND Heart failure (HF) is increasing in prevalence and is a major cause of morbidity and mortality despite advances in medical and device therapy. Autonomic imbalance, with excess sympathetic activation and decreased vagal tone, is an integral component of the pathophysiology of HF. OBJECTIVES The INOVATE-HF (Increase of Vagal Tone in Heart Failure) trial assessed the safety and efficacy of vagal nerve stimulation (VNS) among patients with HF and a reduced ejection fraction. METHODS INOVATE-HF was a multinational, randomized trial involving 85 centers including patients with chronic HF, New York Heart Association functional class III symptoms and ejection fraction RESULTS Patients (n = 707) were randomized and followed up for a mean of 16 months. The primary efficacy outcome occurred in 132 of 436 patients in the VNS group, compared to 70 of 271 in the control group (30.3% vs. 25.8%; hazard ratio: 1.14; 95% confidence interval: 0.86 to 1.53; p = 0.37). During the trial, the estimated annual mortality rates were 9.3% and 7.1%, respectively (p = 0.19). Quality of life, New York Heart Association functional class, and 6-min walking distance were favorably affected by VNS (p <0.05), but left ventricular end-systolic volume index was not different (p = 0.49). CONCLUSIONS VNS does not reduce the rate of death or HF events in chronic HF patients. (INcrease Of VAgal TonE in CHF [INOVATE-HF]; NCT01303718) (C) 2016 by the American College of Cardiology Foundation