A Copper(II) Tris-imidazolylphosphine Complex as a Structural and Functional Model of Flavonol 2,4-Dioxygenase

Reaction of tetrakis(acetonitrile)copper(I) perchlorate ([Cu(NCCH3)4][ClO4]), tris-1-ethyl-4-methylimidazolylphosphine (T1Et4MeIP) (1) and 3-hydroxyflavone (flavH) under ambient conditions produces an in-situ generated flavonol bound copper(II) complex, which converts to a stable green complex that formulates to [Cu(T1Et4MeIP)(flav)][ClO4] (2). The crystal structure of 2 was determined by X-ray diffraction and crystallizes in a triclinic system (P1¯ role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 14.4px; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative; \u3e1¯) with unit cell dimensions of a = 14.537(15) Å, b = 15.794(14) Å, c = 17.044(17) Å, α = 65.58(3)˚, β = 86.80(5)˚, γ = 73.34(4)˚, V = 3376(6) Å3 and Z = 2. While the five-coordinate copper(II) complex is stable under ambient conditions in the solid state, it undergoes oxidative scission of the flavonol pyrone ring under photolytic (300 nm) and/or thermal (120 °C) conditions in the presence of molecular oxygen. The degradative process produces the corresponding methylated products: methylbenzoate, methyl salicylate and N,N-dimethylbenzamide. In addition, the previously undisclosed single crystal X-ray structure of tris-1-ethyl-4-methylimidazolylphosphine (1), T1Et4MeIP, is also reported

Specific and Sensitive Hydrolysis Probe-Based Real-Time PCR Detection of Epidermal Growth Factor Receptor Variant III in Oral Squamous Cell Carcinoma

BACKGROUND: The tumor-specific EGFR deletion mutant, EGFRvIII, is characterised by ligand-independent constitutive signalling. Tumors expressing EGFRvIII are resistant to current EGFR-targeted therapy. The frequency of EGFRvIII in head and neck squamous cell carcinoma (HNSCC) is disputed and may vary by specific sub-site. The purpose of this study was to measure the occurrence of EGFRvIII mutations in a specific HNSCC subsite, oral squamous cell carcinoma (OSCC), using a novel real-time PCR assay. METHODOLOGY: Pre-treatment Formalin Fixed Paraffin Embedded (FFPE) cancer specimens from 50 OSCC patients were evaluated for the presence of EGFRvIII using a novel hydrolysis probe-based real-time PCR assay. EGFR protein expression in tumor samples was quantified using fluorescent immunohistochemistry (IHC) and AQUA® technology. PRINCIPAL FINDINGS: We detected EGFRvIII in a single OSCC patient in our cohort (2%). We confirmed the validity of our detection technique in an independent cohort of glioblastoma patients. We also compared the sensitivity and specificity of our novel real-time EGFRvIII detection assay to conventional RT-PCR and direct sequencing. Our assay can specifically detect EGFRvIII and can discriminate against wild-type EGFR in FFPE tumor samples. AQUAnalysis® revealed that the presence of EGFRvIII transcript is associated with very high EGFR protein expression (98(th) percentile). Contrary to previous reports, only 44% of OSCC over-expressed EGFR in our study. CONCLUSION AND SIGNIFICANCE: Our results suggest that the EGFRvIII mutation is rare in OSCC and corroborate previous reports of EGFRvIII expression only in tumors with extreme over-expression of EGFR. We conclude that EGFRvIII-specific therapies may not be ideally suited as first-line treatment in OSCC. Furthermore, highly specific and sensitive methods, such as the real-time RT-PCR assay and AQUAnalysis® described here, will provide accurate assessment of EGFR mutation frequency and EGFR expression, and will facilitate the selection of optimal tailored therapies for OSCC patients

Efficacy and safety of flexible versus rigid endoscopic third ventriculostomy in pediatric and adult populations: a systematic review and meta-analysis

Endoscopic third ventriculostomy (ETV) is a well-established surgical procedure for hydrocephalus treatment, but there is sparse evidence on the optimal choice between flexible and rigid approaches. A meta-analysis was conducted to compare efficacy and safety profiles of both techniques in pediatrics and adults. A comprehensive search was conducted on PubMED, EMBASE, and Cochrane until 11/10/2019. Efficacy was evaluated comparing incidence of ETV failure, while safety was defined by the incidence of perioperative complications, intraoperative bleedings, and deaths. Random-effects models were used to pool the incidence. Out of 1365 studies, 46 case series were meta-analyzed, yielding 821 patients who underwent flexible ETV and 2918 who underwent rigid ETV, with an age range of [5 days-87 years]. Although flexible ETV had a higher incidence of failure in adults (flexible: 54%, 95%CI: 22-82% vs rigid: 20%, 95%CI: 22-82%) possibly due to confounding due to etiology in adults treated with flexible, a smaller difference was seen in pediatrics (flexible: 36%, pediatric: 32%). Safety profiles were acceptable for both techniques, with a certain degree of variability for complications (flexible 2%, rigid 18%) and death (flexible 1%, rigid 3%) in pediatrics as well as complications (rigid 9%, flexible 13%), death (flexible 4%, rigid 6%) and intra-operative bleeding events (rigid 6%, flexible 8%) in adults. No clear superiority in efficacy could be depicted between flexible and rigid ETV for hydrocephalus treatment. Safety profiles varied by age but were acceptable for both techniques. Well-designed comparative studies are needed to assess the optimal endoscopic treatment option for hydrocephalus

Novel mechanism of inhibition of human angiotensin-I-converting enzyme (ACE) by a highly specific phosphinic tripeptide

Human ACE (angiotensin-I-converting enzyme) has long been regarded as an excellent target for the treatment of hypertension and related cardiovascular diseases. Highly potent inhibitors have been developed and are extensively used in the clinic. To develop inhibitors with higher therapeutic efficacy and reduced side effects, recent efforts have been directed towards the discovery of compounds able to simultaneously block more than one zinc metallopeptidase (apart from ACE) involved in blood pressure regulation in humans, such as neprilysin and ECE-1 (endothelin-converting enzyme-1). In the present paper, we show the first structures of testis ACE [C-ACE, which is identical with the C-domain of somatic ACE and the dominant domain responsible for blood pressure regulation, at 1.97Å (1 Å=0.1 nm)] and the N-domain of somatic ACE (N-ACE, at 2.15Å) in complex with a highly potent and selective dual ACE/ECE-1 inhibitor. The structural determinants revealed unique features of the binding of two molecules of the dual inhibitor in the active site of C-ACE. In both structures, the first molecule is positioned in the obligatory binding site and has a bulky bicyclic P1′ residue with the unusual R configuration which, surprisingly, is accommodated by the large S2′ pocket. In the C-ACE complex, the isoxazole phenyl group of the second molecule makes strong pi–pi stacking interactions with the amino benzoyl group of the first molecule locking them in a ‘hand-shake’ conformation. These features, for the first time, highlight the unusual architecture and flexibility of the active site of C-ACE, which could be further utilized for structure-based design of new C-ACE or vasopeptidase inhibitors

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV