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Background: First-line therapy for advanced oesophageal cancer is currently limited to fluoropyrimidine plus platinum-based chemotherapy. We aimed to evaluate the antitumour activity of pembrolizumab plus chemotherapy versus chemotherapy alone as first-line treatment in advanced oesophageal cancer and Siewert type 1 gastro-oesophageal junction cancer., Methods: We did a randomised, placebo-controlled, double-blind, phase 3 study across 168 medical centres in 26 countries. Patients aged 18 years or older with previously untreated, histologically or cytologically confirmed, locally advanced, unresectable or metastatic oesophageal cancer or Siewert type 1 gastro-oesophageal junction cancer (regardless of PD-L1 status), measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1, and Eastern Cooperative Oncology Group performance status of 0-1, were randomly assigned (1:1) to intravenous pembrolizumab 200 mg or placebo, plus 5-fluorouracil and cisplatin (chemotherapy), once every 3 weeks for up to 35 cycles. Randomisation was stratified by geographical region, histology, and performance status. Patients, investigators, and site staff were masked to group assignment and PD-L1 biomarker status. Primary endpoints were overall survival in patients with oesophageal squamous cell carcinoma and PD-L1 combined positive score (CPS) of 10 or more, and overall survival and progression-free survival in patients with oesophageal squamous cell carcinoma, PD-L1 CPS of 10 or more, and in all randomised patients. This trial is registered with ClinicalTrials.gov, NCT03189719, and is closed to recruitment., Findings: Between July 25, 2017, and June 3, 2019, 1020 patients were screened and 749 were enrolled and randomly assigned to pembrolizumab plus chemotherapy (n=373 [50%]) or placebo plus chemotherapy (n=376 [50%]). At the first interim analysis (median follow-up of 22·6 months), pembrolizumab plus chemotherapy was superior to placebo plus chemotherapy for overall survival in patients with oesophageal squamous cell carcinoma and PD-L1 CPS of 10 or more (median 13·9 months vs 8·8 months; hazard ratio 0·57 [95% CI 0·43-0·75]; p<0·0001), oesophageal squamous cell carcinoma (12·6 months vs 9·8 months; 0·72 [0·60-0·88]; p=0·0006), PD-L1 CPS of 10 or more (13·5 months vs 9·4 months; 0·62 [0·49-0·78]; p<0·0001), and in all randomised patients (12·4 months vs 9·8 months; 0·73 [0·62-0·86]; p<0·0001). Pembrolizumab plus chemotherapy was superior to placebo plus chemotherapy for progression-free survival in patients with oesophageal squamous cell carcinoma (6·3 months vs 5·8 months; 0·65 [0·54-0·78]; p<0·0001), PD-L1 CPS of 10 or more (7·5 months vs 5·5 months; 0·51 [0·41-0·65]; p<0·0001), and in all randomised patients (6·3 months vs 5·8 months; 0·65 [0·55-0·76]; p<0·0001). Treatment-related adverse events of grade 3 or higher occurred in 266 (72%) patients in the pembrolizumab plus chemotherapy group versus 250 (68%) in the placebo plus chemotherapy group., Interpretation: Compared with placebo plus chemotherapy, pembrolizumab plus chemotherapy improved overall survival in patients with previously untreated, advanced oesophageal squamous cell carcinoma and PD-L1 CPS of 10 or more, and overall survival and progression-free survival in patients with oesophageal squamous cell carcinoma, PD-L1 CPS of 10 or more, and in all randomised patients regardless of histology, and had a manageable safety profile in the total as-treated population., Funding: Merck Sharp & Dohme., Competing Interests: Declaration of interests J-MS reports research funding to the institution by Merck Sharp & Dohme (MSD; a subsidiary of Merck), AstraZeneca, and Ono Pharmaceuticals, during the conduct of the study. LS reports research funding to the institution by MSD, grants from Beijing Xiantong Biomedical Technology, Qily Pharmaceutical, Zaiding Pharmaceutical, Jacobio Pharmaceuticals, and Beihai Kangcheng Medical Technology, and consulting fees from HARBOUR and Merck, during the conduct of the study. MAS reports funding to the institution from MSD, Bristol Myers Squibb (BMS), and Oncolys BioPharma, during the conduct of the study. PE reports funding to the institution from MSD, during the conduct of the study, and personal fees from MSD, AstraZeneca, Celgene, Daiichi Sankyo, Five Prime, Lilly, Loxo, Taiho, Takeda, and Zymeworks, outside of the submitted work. AA reports funding to the institution from MSD, BMS, and Bayer Pharmaceuticals, during the conduct of the study, and personal fees from MSD and BMS, and personal fees for advisory role from Merck Serono and Servier, outside of the submitted work. TD reports funding to the institution from MSD, Daiichi Sankyo, Sumitomo Dainippon, AbbVie, Novartis, Boehringer Ingelheim, Taiho Pharmaceutical, Merck Serono, BMS, Pfizer, Lilly, Kyowa Hakko, Kirin, and IQVIA, during the conduct of the study, and personal fees for consulting or advisory role from MSD, Daiichi Sankyo, Amgen, Sumitomo Dainippon, Taiho Pharmaceutical, Takeda, AbbVie, Novartis, Bayer, Boehringer Ingelheim, Rakuten Medical, and BMS, and honoraria from Ono Pharmaceutical, Astellas Pharma, Oncolys BioPharma, Taiho Pharmaceutical, and Otsuka, outside of the submitted work. TK reports funding to the institution from MSD, Ono Pharmaceutical, Shionogi, Astellas Amgen Bio Pharma, and Taiho Pharmaceutical, during the conduct of the study, and personal fees from MSD, Ono Pharmaceutical, Merck, Astellas Pharma, BMS, and Oncolys BioPharma, outside of the submitted work. J-PM reports funding to the institution from MSD, during the conduct of the study, and honoraria from MSD, Bayer, and BMS, outside of the submitted work. ZL reports funding to the institution from MSD, during the conduct of the study. S-BK reports funding to the institution from MSD, Novartis, and Sanofi-Genzyme, during the conduct of the study, and personal fees for consulting or advisory role from Dae Hwa Pharmaceutical, ISU Abxis, and Daiichi-Sankyo, outside of the submitted work. BCC reports funding to the institution from MSD, Novartis, Bayer, AstraZeneca, MOGAM Institute, Dong-A ST, Champions Oncology, Janssen, Yuhan, Ono, Dizal Pharma, AbbVie, Medpacto, G Innovation, Eli Lilly, Blueprint Medicines, and Interpark Bio Convergence, fees for consulting or advisory role from Novartis, AstraZeneca, Boehringer Ingelheim, Roche, BMS, Ono, Yuhan, Pfizer, Eli Lilly, Janssen, Takeda, MSD, Janssen, Medpacto, Blueprint Medicines, KANAPH Therapeutic, Brigebio Therapeutics, Cyrus Therapeutics, and Guardant Health, stock ownership in TheraCanVac, Gencurix, Bridgebio Therapeutics, KANAPH Therapeutic, Cyrus Therapeutics, and Interpark Bio Convergence, personal fees for Board of Directorship from Gencurix and Interpark Bio Convergence, royalties from Champions Oncology, and is the founder of DAAN Biotherapeutics, outside of the submitted work. MAM reports funding to the institution from MSD, during the conduct of the study, and consultancy for MSD, BMS, Servier, and Lilly, and honoraria from BMS, Servier, and Amgen, outside of the submitted work. EG reports funding to the institution from MSD, during the conduct of the study, and personal fees from MSD, BMS, Servier, and Roche, outside of the submitted work. HH reports funding to the institution from MSD, during the conduct of the study, and grants from AstraZeneca, Daiichi Sankyo, Dainippon Sumitomo Pharma, Merck Biopharma, MSD, Taiho, Chugai, Eisai, LSK BioPharma, Incyte, Pfizer, Boehringer Ingelheim, Beigene, Ono, BMS, and Astellas, and personal fees from Daiichi Sankyo, Dainippon Sumitomo Pharma, Lilly, Merck Biopharma, MSD, Taiho, Chugai, Ono, BMS, Yakult Honsha, Sanofi, Takeda, and Kyowa Hakko Kirin, outside of the submitted work. CF reports funding to the institution from MSD, during the conduct of the study, and grants and non-financial support from National Comprehensive Cancer Network, Taiho Oncology, Pfizer, and AstraZeneca, outside of the submitted work. AT reports funding to the institution from MSD, during the conduct of the study, and grants from Taiho Pharmaceutical, Chugai Pharmaceutical, Eli Lilly Japan, Merck Biopharma, Takeda Pharmaceutical, Sanofi, Ono Pharmaceutical, Kyowa Hakko Kirin, Eisai, Toray Medical, Daiichi Sankyo, Bayer Yakuhin, Shionogi, Pfizer, and Yakult Honsha, and personal fees from Taiho Pharmaceutical, Chugai Pharmaceutical, Eli Lilly, BMS, Merck Biopharma, Takeda Pharmaceutical, and Sanofi, outside of the submitted work. WM, S-HL, PS, LA, and VCO report funding to the institution from MSD, during the conduct of the study. QL, SS, and PB are employees and hold stock in MSD. KK reports funding to the institution from MSD, during the conduct of the study, and research funding from Ono, BMS, Beigene, Shionogi, Merck Biopharma, Oncolys Biopharma, and Chugai, outside of the submitted work., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Stannous fluoride (SnF 2 ) is a compound present in many commercially available dentifrices; however, oxidative decomposition negatively impacts its efficacy. Stannous oxidation is often mitigated through the addition of complexing agents or sources of sacrificial stannous compounds. The authors have found that the addition of zinc phosphate significantly improved stannous stability more effectively than other stabilization methods. The authors evaluated the chemical speciation of stannous compounds within a variety of formulations using x-ray absorption near edge spectroscopy (XANES), a technique never used before in this manner. These data were compared and correlated with several antimicrobial experiments., Methods: XANES data of various commercially available compounds and Colgate Total SF were performed and analyzed against a library of reference compounds to determine the tin chemical speciation. The antibacterial assays used were salivary adenosine triphosphate, short-interval kill test, plaque glycolysis, and anaerobic biofilm models., Results: XANES spectra showed a diverse distribution of tin species and varying degrees of SnF 2 oxidation. In vitro antimicrobial assessment indicated significant differences in performance, which may be correlated to the differences in tin speciation and oxidation state., Conclusions: Driven by the excipient ingredients, SnF 2 dentifrices contain a distribution of tin species in either the SnF 2 or Sn(IV) oxidation state. The addition of zinc phosphate provided significant robustness against oxidation, which directly translated to greater efficacy against bacteria., Practical Implications: The choice of inactive ingredients in a dentifrice with active SnF 2 can dramatically impact product stability., (Copyright © 2019 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Identifying and quantifying the processes governing the mobilization of metals during resuspension events is key to assessing long-term metals efflux from sediments and associated ecological impacts. We investigated the effects of sediment resuspension on the mobilization and chemical speciation of zinc in two-week-long batch experiments using metal-contaminated sediments from Lake DePue (IL, USA). Measurements of dissolved zinc and sulfate allowed us to characterize the kinetics of metal sulfide dissolution and the resulting net release of zinc to the aqueous phase. X-ray absorption spectroscopy (XAS) provided direct insights into the chemical speciation of iron and zinc and their dynamic transformations during resuspension. While ZnS rapidly oxidized during resuspension, dissolved zinc increased only after two days of resuspension. We proposed a kinetic model to explain changes in the chemical speciation of zinc during these experiments as constrained by the dissolved species concentrations and chemical speciation as informed by XAS. Only 15% of the zinc mobilized was released to the aqueous phase while the remaining fraction repartitioned the solid phase either as a carbonate precipitate or as a sorbed species. Our results show that zinc sorption onto particle surfaces and reprecipitation of zinc minerals limit zinc solubility during resuspension of metal-sulfide sediments., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In order to determine the ability of 1,2-dipalmitoyl phosphatidylcholine (DPPC) and 1,2-dioleoyl phosphatidylglycerol (DOPG) to host peptide sequences belonging to the E2 protein of GBV virus C/Hepatitis G virus, the behaviour of Langmuir monolayers formed by these phospholipids and E2 (12-26), E2 (354-363) and E2 (chimeric) peptide sequences was analysed from data of surface pressure (π) versus area per molecule (A) isotherms, compression modulus (C s -1 ), excess Gibbs energy of mixing (ΔG exc ) and total Gibbs energy of mixing (ΔG mix ). Three different behaviours were observed. Mixed films of E2 (12-26) with DPPC or DOPC showed negative values for the excess thermodynamic functions, and thus attractive interactions between mixed films components are greater than in ideal films. Mixtures of E2 (354-363) with DPPC or DOPG, exhibited positive values of excess functions, evidencing weaker interactions in the mixed films in relation to those of pure components. Finally, positive and negative excess functions were observed in E2 (chimeric)/DPPC or DOPG mixed films, depending on their composition. In short, the interaction between the phospholipids used in this work as models of cell membranes and E2 peptides varies with the type of phospholipid and the nature of the peptide (size, bulky, hydrophobicity and electric charge)., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Microbially influenced corrosion (MIC) is recognized as an unusual and severe type of corrosion that causes costly failures around the world. A microbial biofilm could enhance the copper release from copper plumbing into the water by forming a reactive interface. The biofilm increases the corrosion rate, the mobility of labile copper from its matrix and the detachment of particles enriched with copper under variable shear stress due to flow conditions. MIC is currently considered as a series of interdependent processes occurring at the metal-liquid interface. The presence of a biofilm results in the following effects: (a) the formation of localized microenvironments with distinct pH, dissolved oxygen concentrations, and redox conditions; (b) sorption and desorption of labile copper bonded to organic compounds under changing water chemistry conditions; (c) change in morphology by deposition of solid corrosion by-products; (d) diffusive transport of reactive chemical species from or towards the metal surface; and (e) detachment of scale particles under flow conditions. Using a multi-technique approach that combines pipe and coupon experiments this paper reviews the effects of microbial biofilms on the corrosion of copper plumbing systems, and proposes an integrated conceptual model for this phenomenon supported by new experimental data., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The physical chemistry properties and interactions of E2 (125-139) and E2 (120-139) peptide sequences from GB virus C with model cell membranes were investigated by means of several biophysical techniques in order to gain better understanding of the effect of peptide length and lipid charge on membrane binding. The peptides, having one net negative charge at the pH of the assays, interacted with monolayers of all the phospholipids regardless of the charge but with more extent with the cationic DPTAP thus indicating that the interaction had both a hydrophobic and an electrostatic component as has been observed for other peptides of the same family. The peptides were able to leakage contents of liposomes and showed fluorescence energy transfer in vesicles depending on the vesicles lipid composition. On another hand, circular dichroism has shown that the peptides exist mainly as a mixture of disordered structure and β-type conformations in aqueous solution but diminished its unstructured content, folding preferentially into α-helical conformation upon interaction with hydrophobic solvents or positively charged lipid surfaces. Altogether, results of this work indicate that the peptides interact at a surface level, penetrate into bilayers composed of fluid lipids and that conformational changes could be responsible for this effect., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Three hydrophobic derivatives of GHK peptide containing either N-terminal hexanoyl, decanoyl or myristoyl acyl moieties were synthesized. The binding of these peptidolipids to phospholipid bilayers as well as their hemolytic activity were determined. Moreover, the influence of these peptidolipids on several physicochemical properties of liposomes was studied. Binding experiments indicate a high affinity of these peptidolipids for lipids ordered in liposomes. Nevertheless, this interaction does not promote the release of entrapped carboxyfluorescein. Experiments carried out by the asymmetric membrane method (NBD-PE/dithionite) and quenching studies (PC-pyrene/KI) indicate that this association has a protective effect suggesting that the hydrophobic moiety inserts in the external part of the bilayer and the peptide chain remains protruding from the surface hindering the entrance or the approach of reactants to it. The microviscosity of DPPC bilayers determined using TMA-DPH as fluorescent marker was not affected by the presence of peptidolipids. Besides, results indicate that myristoyl-GHK produces total hemolysis at 2.5x10(-4)M but decanoyl and hexanoyl derivatives at 5x10(-4)M induce only 10% of hemolysis.

With the aim of better understanding the fusion process mediated by the envelope proteins of the hepatitis G virus (HGV/GBV-C), we have investigated the interaction with model membranes of two overlapping peptides [(267-284) and (279-298)] belonging to the E2 structural protein. The peptides were compared for their ability to perturb lipid bilayers by means of different techniques such as differential scanning calorimetry and fluorescence spectroscopy. Furthermore, the conformational behaviour of the peptides in different membrane environments was studied by Fourier-transform infrared spectroscopy and circular dichroism. The results showed that only the E2(279-298) peptide sequence was able to bind with high affinity to negatively charged membranes, to permeabilize efficiently negative lipid bilayers, to induce haemolysis, and to promote inter-vesicle fusion. This fusogenic activity could be related to the induced peptide conformation upon interaction with the target membrane.

The membrane-interacting properties of two potential epitopes of the GB virus C/Hepatitis G virus, located respectively at the regions (99-118) of the E2 structural protein and (440-460) of the NS3 non-structural protein were studied. Changes in the intrinsic fluorescence of Trp and Tyr residues after the addition of DPPC-LUV revealed that the peptide-membrane interaction was optimal above the gel-liquid crystalline transition temperature of the lipid. Differential scanning calorimetry studies showed that the E2 peptide incorporated into lipid bilayers perturbs the packing of lipids and affects their thermotropic properties. Moreover, the 20-mer structural peptide induced a slow leakage of vesicular contents at 55 degrees C.

Merocyanine 540 (MC540) has been used as external probe to determine the interaction of the peptide sequence 125-139 corresponding to the E2 protein of Hepatitis G virus, with lipid bilayers. The probe was incorporated into large unilamellar vesicles (LUVs) or small unilamellar vesicles (SUVs) of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). When incorporated into bilayers, MC540 shows two absorption maxima corresponding to the monomer (570 nm) and dimer (530 nm) form of the probe. Changes in the probe microenvironment are reflected by a modification in the position and/or intensity of these maxima. Addition of increasing amounts of peptide resulted in a slight decrease of the ratio A570/A530 thus indicating a change in MC540 partition into the membrane, going from a hydrophobic to a more hydrophilic environment. This effect was concomitant with an increase in dimer formation as stated from the values of the apparent dimerization constant (K(app)) obtained. Fluorescence spectra as well as steady state anisotropy measurements were in agreement with the above results indicating that the peptide was able to relocate the probe and displacing MC540 from its initial location into the bilayer. Results with SUVs or LUVs were similar for what curvature does not seem to play any role on peptide activity. These results reflect the ability of peptide to interact with biomimetic membranes in the lipid head group region.

Polymyxins are a family of nonribosomic cationic peptide antibiotics highly effective against Gram-negative bacteria. Two members of this family, Polymyxins B and E (PxB, PxE), form molecular vesicle-vesicle contacts and promote a selective exchange of phospholipids at very low concentrations in the membrane, a biophysical phenomenon that can be the basis of their antibiotic mode of action. To get more insight into the interaction of these antibiotics with the lipid membrane, their effect on the structural dynamics of bilayers prepared with lipids extracted from the membrane of Escherichia coli was determined using fluorescently labeled phopholipids. Steady-state anisotropy measurements with probes that localize at different positions in the membrane give information on the effects of polymyxins on the mobility of the phospholipids. Results with PxB, PxE, colymycin M and polymyxin B nonapeptide (PxB-NP), a deacylated derivative with no antibiotic properties, are compared. At low peptide concentrations (<2 mol%) PxB and PxE bind to the membranes superficially, affecting very slightly the ordering of the lipids at the outermost part of the bilayer. Above this concentration, PxB and PxE insert more deeply in the bilayer, increasing lipid order both in the gel and liquid-crystal states and modifying phase transitions. Fluorescence experiments with pyrene labeled phospholipids indicate that the increase in lipid packing is accompanied by an enrichment of phospholipids in the bilayers. In contrast, colymycin M and PxB-NP did not modify lipid packing or phase transition, nor did they induce microdomain formation. The possible significance of these results in the antibiotic mode of action of PxB and PxE is discussed. The combination of spectroscopic techniques described here can be useful as part of a general method of screening for new antibiotics that act on the membrane by the same mechanism as polymyxins.

In the present work we demonstrate the application of a commercial biosensor instrument (BIACORE 1000, Biacore AB, Uppsala) for the detection of antibodies against the hepatitis A virus (HAV) in human serum samples using linear and branched synthetic peptides related to the VP3 capsid protein of HAV. We also studied the conformation of the synthetic peptides by circular dichroism (CD) in order to analyse the changes in secondary structure of the constructs that could influence their recognition by antibodies. Linear and dimeric VP3(110-121) multiple antigen peptides (MAP) were the most sensitive and appropriate for serological studies of serum from HAV infected patients using BIACORE. Immobilization of tetrameric MAPs via amine groups apparently failed to preserve the active conformation of the peptide epitope since it led to lower antibody binding compared to linear and dimeric peptides. The CD analysis showed that the tetrameric MAP constructs tend to adopt a beta-sheet structure due to intermolecular aggregation, which limits epitope accessibility. Our results demonstrate the value of biospecific interaction analysis technology using synthetic peptides for the diagnosis of acute hepatitis A.

Transferrin was incorporated into the external surface of liposomes that were previously derivatized with ceramides. This new hydrophobic derivative of transferrin was incubated with liposomes at different protein-to-lipid ratios. The surface activity of both native and derivatized transferrin was determined with monomolecular layers as a membrane model. The maximal interaction was found with dipalmitoylphosphatidylcholine in all the experiences.

The interaction of opiate molecules (buprenorphine, codeine, dextromethorphan, diprenorphine, etorphine, meperidine, methadone, morphine, and naloxone) with lipids (phosphatidylcholine, phosphatidylinositol, phatidylinositol, phosphatidylserine, and cholesterol) by using liposomes and monomolecular layers as membrane models is described. The ability of opiates to induce leakage of carboxyfluorescin from liposomes is highly dependent on the hydrophobicity of the opiate molecules. Buprenorphine and etorphine increased the membrane permeability in all the experiments. On the contrary, naloxone, morphine, and codeine only caused a slight release of the entrapped dye in the presence of acidic phospholipids. Moreover, the leakage of carboxyfluorescein is directly related to the concentration of drug in the incubation media. Studies of the kinetics of the surface penetration of these molecules into monolayers of phospholipids were performed. Again, in this system, buprenorphine and etorphine exhibited stronger interactions than the most hydrophilic opiates. Nevertheless, in these experiments, differences among the opiate molecules are not so high as in the liposomes. The time course of the penetration of all of these molecules in the monolayers fits the Lineweaver-Burk equation. This fact suggests a lack of specific interactions and the predominance of hydrophobic factors. Moreover, the high percentage of release of entrapped dye caused by some opiate molecules suggests a possible toxic side-effect for these agents.

Monomolecular films of lecithin, gangliosides or lecithin/gangliosides mixtures were studied on a Langmuir through in order to examine the interactions between these lipids and opioid agonists or antagonists. Lecithin alone did not interact in a monolayer structure with opioids. However, gangliosides and lecithin/gangliosides mixtures were expanded by both morphine and naloxone. The expansion of ganglioside-containing monolayers was greater with morphine than with the antagonist, naloxone.