May I have your consent? Informed consent in clinical trials- feasibility in emergency situations

Clinical researchers in acute emergency settings are commonly faced with the difficulty of satisfying the conventional ethical requirement of obtaining informed consent, whilst ensuring a representative group of patients is recruited into studies. We discuss our own experience in addressing institutional ethical requirements to obtain informed consent in a multi-centre trial, recruiting highly agitated patients in the emergency setting in Melbourne, Australia. We suggest that, through the application of existing ethical and legal frameworks and pre-emptive communication with the key stakeholders in ethics committees, hospital insurers and legal representatives, a balance can be struck between ethical and legal requirements on the one hand, and the integrity of the research question, on the other.published_or_final_versio

Intravenous Midazolam-Droperidol (combination), Droperidol (only) or Olanzapine (only) for the acutely agitated patient: A multi-centred, randomised, double-blind, triple-dummy, clinical trial

AIM: To determine the most efficacious of three currently used drug regimens for the sedation of acutely agitated patients in the emergency department ...postprin

Midazolam-droperidol, droperidol or olanzapine for acute agitation: a randomised clinical trial

STUDY OBJECTIVE: We aim to determine the most efficacious of 3 common medication regimens for the sedation of acutely agitated emergency department (ED) patients. METHODS: We undertook a randomized, controlled, double-blind, triple-dummy, clinical trial in 2 metropolitan EDs between October 2014 and August 2015. Patients aged 18 to 65 years and requiring intravenous medication sedation for acute agitation were enrolled and randomized to an intravenous bolus of midazolam 5 mg-droperidol 5 mg, droperidol 10 mg, or olanzapine 10 mg. Two additional doses were administered, if required: midazolam 5 mg, droperidol 5 mg, or olanzapine 5 mg. The primary outcome was the proportion of patients adequately sedated at 10 minutes. RESULTS: Three hundred forty-nine patients were randomized to the 3 groups. Baseline characteristics were similar across the groups. Ten minutes after the first dose, significantly more patients in the midazolam-droperidol group were adequately sedated compared with the droperidol and olanzapine groups: differences in proportions 25.0% (95% confidence interval [CI] 12.0% to 38.1%) and 25.4% (95% CI 12.7% to 38.3%), respectively. For times to sedation, the differences in medians between the midazolam-droperidol group and the droperidol and olanzapine groups were 6 (95% CI 3 to 8) and 6 (95% CI 3 to 7) minutes, respectively. Patients in the midazolam-droperidol group required fewer additional doses or alternative drugs to achieve adequate sedation. The 3 groups' adverse event rates and lengths of stay did not differ. CONCLUSION: Midazolam-droperidol combination therapy is superior, in the doses studied, to either droperidol or olanzapine monotherapy for intravenous sedation of the acutely agitated ED patient. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.postprin

Economic evaluation of midazolam–droperidol combination, versus droperidol or olanzapine for the management of acute agitation in the emergency department: A within-trial analysis

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Sedating the agitated patient: a moving target? – In reply

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An Innovative Strategy for Dual Inhibitor Design and Its Application in Dual Inhibition of Human Thymidylate Synthase and Dihydrofolate Reductase Enzymes

Due to the diligence of inherent redundancy and robustness in many biological networks and pathways, multitarget inhibitors present a new prospect in the pharmaceutical industry for treatment of complex diseases. Nevertheless, to design multitarget inhibitors is concurrently a great challenge for medicinal chemists. We have developed a novel computational approach by integrating the affinity predictions from structure-based virtual screening with dual ligand-based pharmacophore to discover potential dual inhibitors of human Thymidylate synthase (hTS) and human dihydrofolate reductase (hDHFR). These are the key enzymes in folate metabolic pathway that is necessary for the biosynthesis of RNA,DNA, and protein. Their inhibition has found clinical utility as antitumor, antimicrobial, and antiprotozoal agents. A druglike database was utilized to perform dual-target docking studies. Hits identified through docking experiments were mapped over a dual pharmacophore which was developed from experimentally known dual inhibitors of hTS and hDHFR. Pharmacophore mapping procedure helped us in eliminating the compounds which do not possess basic chemical features necessary for dual inhibition. Finally, three structurally diverse hit compounds that showed key interactions at both activesites, mapped well upon the dual pharmacophore, and exhibited lowest binding energies were regarded as possible dual inhibitors of hTS and hDHFR. Furthermore, optimization studies were performed for final dual hit compound and eight optimized dual hits demonstrating excellent binding features at target systems were also regarded as possible dual inhibitors of hTS and hDHFR. In general, the strategy used in the current study could be a promising computational approach and may be generally applicable to other dual target drug designs

A framework for the definition and interpretation of the use of surrogate endpoints in interventional trials

Background: Interventional trials that evaluate treatment effects using surrogate endpoints have become increasingly common. This paper describes four linked empirical studies and the development of a framework for defining, interpreting and reporting surrogate endpoints in trials. Methods: As part of developing the CONSORT (Consolidated Standards of Reporting Trials) and SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) extensions for randomised trials reporting surrogate endpoints, we undertook a scoping review, e-Delphi study, consensus meeting, and a web survey to examine current definitions and stakeholder (including clinicians, trial investigators, patients and public partners, journal editors, and health technology experts) interpretations of surrogate endpoints as primary outcome measures in trials. Findings: Current surrogate endpoint definitional frameworks are inconsistent and unclear. Surrogate endpoints are used in trials as a substitute of the treatment effects of an intervention on the target outcome(s) of ultimate interest, events measuring how patients feel, function, or survive. Traditionally the consideration of surrogate endpoints in trials has focused on biomarkers (e.g., HDL cholesterol, blood pressure, tumour response), especially in the medical product regulatory setting. Nevertheless, the concept of surrogacy in trials is potentially broader. Intermediate outcomes that include a measure of function or symptoms (e.g., angina frequency, exercise tolerance) can also be used as substitute for target outcomes (e.g., all-cause mortality)—thereby acting as surrogate endpoints. However, we found a lack of consensus among stakeholders on accepting and interpreting intermediate outcomes in trials as surrogate endpoints or target outcomes. In our assessment, patients and health technology assessment experts appeared more likely to consider intermediate outcomes to be surrogate endpoints than clinicians and regulators. Interpretation: There is an urgent need for better understanding and reporting on the use of surrogate endpoints, especially in the setting of interventional trials. We provide a framework for the definition of surrogate endpoints (biomarkers and intermediate outcomes) and target outcomes in trials to improve future reporting and aid stakeholders' interpretation and use of trial surrogate endpoint evidence

Novel Cβ–Cγ Bond Cleavages of Tryptophan-Containing Peptide Radical Cations

In this study, we observed unprecedented cleavages of the Cβ–Cγ bonds of tryptophan residue side chains in a series of hydrogen-deficient tryptophan-containing peptide radical cations (M•+) during low-energy collision-induced dissociation (CID). We used CID experiments and theoretical density functional theory (DFT) calculations to study the mechanism of this bond cleavage, which forms [M – 116]+ ions. The formation of an α-carbon radical intermediate at the tryptophan residue for the subsequent Cβ–Cγ bond cleavage is analogous to that occurring at leucine residues, producing the same product ions; this hypothesis was supported by the identical product ion spectra of [LGGGH – 43]+ and [WGGGH – 116]+, obtained from the CID of [LGGGH]•+ and [WGGGH]•+, respectively. Elimination of the neutral 116-Da radical requires inevitable dehydrogenation of the indole nitrogen atom, leaving the radical centered formally on the indole nitrogen atom ([Ind]•-2), in agreement with the CID data for [WGGGH]•+ and [W1-CH3GGGH]•+; replacing the tryptophan residue with a 1-methyltryptophan residue results in a change of the base peak from that arising from a neutral radical loss (116 Da) to that arising from a molecule loss (131 Da), both originating from Cβ–Cγ bond cleavage. Hydrogen atom transfer or proton transfer to the γ-carbon atom of the tryptophan residue weakens the Cβ–Cγ bond and, therefore, decreases the dissociation energy barrier dramatically

Constraints on black-hole charges with the 2017 EHT observations of M87*

Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is already sufficient to rule out that M87* is a highly charged dilaton black hole. Similarly, when considering black holes with two physical and independent charges, we are able to exclude considerable regions of the space of parameters for the doubly-charged dilaton and the Sen black holes

First M87 Event Horizon Telescope Results. VII. Polarization of the Ring

In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in the immediate vicinity of the black hole. Here we present the corresponding linear-polarimetric EHT images of the center of M87. We find that only a part of the ring is significantly polarized. The resolved fractional linear polarization has a maximum located in the southwest part of the ring, where it rises to the level of ~15%. The polarization position angles are arranged in a nearly azimuthal pattern. We perform quantitative measurements of relevant polarimetric properties of the compact emission and find evidence for the temporal evolution of the polarized source structure over one week of EHT observations. The details of the polarimetric data reduction and calibration methodology are provided. We carry out the data analysis using multiple independent imaging and modeling techniques, each of which is validated against a suite of synthetic data sets. The gross polarimetric structure and its apparent evolution with time are insensitive to the method used to reconstruct the image. These polarimetric images carry information about the structure of the magnetic fields responsible for the synchrotron emission. Their physical interpretation is discussed in an accompanying publication