1
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Foglia F, Della Rocca M, Melardo C, Nastri B, Manfredini M, Montella F, De Filippis A, Finamore E, Galdiero M. Bloodstream infections and antibiotic resistance patterns: a six-year surveillance study from southern Italy. Pathog Glob Health 2023; 117:381-391. [PMID: 36190133 PMCID: PMC10177691 DOI: 10.1080/20477724.2022.2129161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2022] Open
Abstract
Bloodstream infections (BSI) are associated with high morbidity and mortality. This study aimed to describe the epidemiology of BSI and antimicrobial resistance patterns amongst its common bacterial causes. We conducted a retrospective record review of blood culture results of patients hospitalized with BSI at University Hospital 'L. Vanvitelli' from 2016 to 2021. For each patient records were obtained from the database using microbiological information. Gram-positive bacteria were the most predominant pathogens followed by Gram-negative bacteria. Among all isolates, bacterial pathogens most frequently identified included coagulase-negative Staphylococci (CoNS), Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and enterococci. We noted a general decrease in antimicrobial resistance amongst BSI pathogens in the latter years of the study. High levels of macrolide and aminoglycoside resistance amongst CoNS were reported. Carbapenem resistance amongst E. coli was barely reported, while resistance rates amongst K. pneumoniae declined considerably between 2018 and 2021. The prevalence of methicillin-resistant S. aureus decreased during the study period while that of methicillin-resistant CoNS remained relatively high throughout. The prevalence of extended spectrum ß-lactamase - producing E. coli increased considerably between 2016 and 2018 but showed a slight decrease thereafter. Conversely, there was a general decline in the resistant rates of extended spectrum ß-lactamase - producing K. pneumoniae between 2016 and 2018 with a similar trend being noted for carbapenem resistance in K. pneumoniae. Continuously monitoring the changes in the trends in BSI microbiological profiles, including pathogen profiles and the associated antibiotic resistance patterns, can help diagnostic approaches, treatment strategies and prevention programs.
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Affiliation(s)
- F. Foglia
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - M.T. Della Rocca
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - C. Melardo
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - B.M. Nastri
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - M. Manfredini
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - F. Montella
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - A. De Filippis
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - E. Finamore
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Massimiliano Galdiero
- Section of Virology and Microbiology, University Hospital of Campania “Luigi Vanvitelli”, Naples, Italy
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
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2
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Foglia F, Berrod Q, Clancy AJ, Smith K, Gebel G, Sakai VG, Appel M, Zanotti JM, Tyagi M, Mahmoudi N, Miller TS, Varcoe JR, Periasamy AP, Brett DJL, Shearing PR, Lyonnard S, McMillan PF. Disentangling water, ion and polymer dynamics in an anion exchange membrane. Nat Mater 2022; 21:555-563. [PMID: 35301475 DOI: 10.1038/s41563-022-01197-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/11/2022] [Indexed: 05/12/2023]
Abstract
Semipermeable polymeric anion exchange membranes are essential for separation, filtration and energy conversion technologies including reverse electrodialysis systems that produce energy from salinity gradients, fuel cells to generate electrical power from the electrochemical reaction between hydrogen and oxygen, and water electrolyser systems that provide H2 fuel. Anion exchange membrane fuel cells and anion exchange membrane water electrolysers rely on the membrane to transport OH- ions between the cathode and anode in a process that involves cooperative interactions with H2O molecules and polymer dynamics. Understanding and controlling the interactions between the relaxation and diffusional processes pose a main scientific and critical membrane design challenge. Here quasi-elastic neutron scattering is applied over a wide range of timescales (100-103 ps) to disentangle the water, polymer relaxation and OH- diffusional dynamics in commercially available anion exchange membranes (Fumatech FAD-55) designed for selective anion transport across different technology platforms, using the concept of serial decoupling of relaxation and diffusional processes to analyse the data. Preliminary data are also reported for a laboratory-prepared anion exchange membrane especially designed for fuel cell applications.
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Affiliation(s)
- Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK.
| | - Quentin Berrod
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France
| | - Adam J Clancy
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK
| | - Keenan Smith
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Gérard Gebel
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton, UK
| | | | - Jean-Marc Zanotti
- Laboratoire Léon Brillouin (CEA-CNRS), Université Paris-Saclay, CEA Saclay, Gif-sur-Yvette Cedex, France
| | - Madhusudan Tyagi
- NIST Center for Neutron Research (NCNR), National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA
| | - Najet Mahmoudi
- ISIS Neutron and Muon Source, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton, UK
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - John R Varcoe
- Department of Chemistry, University of Surrey, Guildford, UK
| | | | - Daniel J L Brett
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Paul R Shearing
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Sandrine Lyonnard
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France.
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK
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3
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Foglia F, Lyonnard S, Sakai VG, Berrod Q, Zanotti JM, Gebel G, Clancy AJ, McMillan PF. Progress in neutron techniques: towards improved polymer electrolyte membranes for energy devices. J Phys Condens Matter 2021; 33:264005. [PMID: 33906172 DOI: 10.1088/1361-648x/abfc10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Design and implementation of advanced membrane formulations for selective transport of ions and molecular species are critical for creating the next generations of fuel cells and separation devices. It is necessary to understand the detailed transport mechanisms over time- and length-scales relevant to the device operation, both in laboratory models and in working systems under realistic operational conditions. Neutron scattering techniques including quasi-elastic neutron scattering, reflectivity and imaging are implemented at beamline stations at reactor and spallation source facilities worldwide. With the advent of new and improved instrument design, detector methodology, source characteristics and data analysis protocols, these neutron scattering techniques are emerging as a primary tool for research to design, evaluate and implement advanced membrane technologies for fuel cell and separation devices. Here we describe these techniques and their development and implementation at the ILL reactor source (Institut Laue-Langevin, Grenoble, France) and ISIS Neutron and Muon Spallation source (Harwell Science and Technology Campus, UK) as examples. We also mention similar developments under way at other facilities worldwide, and describe approaches such as combining optical with neutron Raman scattering and x-ray absorption with neutron imaging and tomography, and carrying out such experiments in specialised fuel cells designed to mimic as closely possible actualoperandoconditions. These experiments and research projects will play a key role in enabling and testing new membrane formulations for efficient and sustainable energy production/conversion and separations technologies.
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Affiliation(s)
- Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, United Kingdom
| | - Sandrine Lyonnard
- University Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, 38000 Grenoble, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton OX11 0QX, United Kingdom
| | - Quentin Berrod
- University Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, 38000 Grenoble, France
| | - Jean-Marc Zanotti
- Laboratoire Léon Brillouin (CEA-CNRS), Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Gérard Gebel
- University Grenoble Alpes, CEA LITEN, 38000 Grenoble, France
| | - Adam J Clancy
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, United Kingdom
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, United Kingdom
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4
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Pink DL, Foglia F, Barlow DJ, Lawrence MJ, Lorenz CD. The Impact of Lipid Digestion on the Dynamic and Structural Properties of Micelles. Small 2021; 17:e2004761. [PMID: 33470509 DOI: 10.1002/smll.202004761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/02/2020] [Indexed: 06/12/2023]
Abstract
Self-assembled, lipid-based micelles, such as those formed by the short-chain phosphocholine, dihexanoylphosphatidylcholine (2C6PC), are degraded by the pancreatic enzyme, phospholipase A2 (PLA2). Degradation yields 1-hexanoyl-lysophosphocholine (C6LYSO) and hexanoic acid (C6FA) products. However, little is known about the behavior of these products during and after the degradation of 2C6PC. In this work, a combination of static and time-resolved small angle neutron scattering, as well as all-atom molecular dynamics simulations, is used to characterize the structure of 2C6PC micelles. In doing so a detailed understanding of the substrate and product aggregation behavior before, during and after degradation is gained. Consequently, the formation of mixed micelles containing 2C6PC, C6LYSO and C6FA is shown at every stage of the degradation process, as well as the formation of mixed C6LYSO/C6FA micelles after degradation is complete. The use of atomistic molecular dynamics has allowed us to characterize the structure of 2C6PC, 2C6PC/C6LYSO/C6FA, and C6LYSO/C6FA micelles throughout the degradation process, showing the localization of the different molecular species within the aggregates. In addition, the hydration of the 2C6PC, C6LYSO, and C6FA species both during micellization and as monomers in aqueous solution is documented to reveal the processes driving their micellization.
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Affiliation(s)
- Demi L Pink
- Department of Physics, King's College London, London, WC2R 2LS, UK
| | - Fabrizia Foglia
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - David J Barlow
- Faculty of Life Sciences and Medicine, King's College London, Franklin-Wilkins Building, Stamford Street, London, SE1 9NH, UK
| | - M Jayne Lawrence
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PL, UK
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5
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Pignataro D, Foglia F, Della Rocca MT, Melardo C, Santella B, Folliero V, Shinde S, Pafundi PC, Sasso FC, Iovene MR, Galdiero M, Boccia G, Franci G, Finamore E, Galdiero M. Methicillin-resistant Staphylococcus aureus: epidemiology and antimicrobial susceptibility experiences from the University Hospital 'Luigi Vanvitelli' of Naples. Pathog Glob Health 2020; 114:451-456. [PMID: 33012280 DOI: 10.1080/20477724.2020.1827197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important pathogens worldwide showing resistance to several widely used antibiotics. This has made the treatment of MRSA infections harder, especially due to their prevalence in the hospital setting. We evaluated the antibiotic susceptibility patterns of healthcare-associated MRSA infections with a focus on Vancomycin Intermediate S. Aureus (VISA) and macrolide-licosamide-streptogramin B (MLSB) phenotypes. A total of 417 Staphylococcus aureus (S. aureus) cases were isolated between January 2017 and December 2018, through several clinical specimens collected from the University Hospital 'Luigi Vanvitelli' of Naples. We identified bacterial strains using Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) and antimicrobial susceptibility using Phoenix BD (Becton Dickinson, NJ, USA). Out of the total 417 S. aureus cases, 140 were MRSA (33.6%) and of these, 50% were soft tissue infections. All MRSA and Methicillin sensible S.aureus MSSA isolates were susceptible to linezolid and daptomycin. Two MRSA cases exhibited intermediate resistance to vancomycin and were of constitutive MLSB phenotype. Among the MRSA strains, 11.4% were constitutive and 43.6% were inducible MLSB phenotypes and 8.6% were macrolide-streptogramin B phenotype. This study characterized the epidemiological status, antibiotic resistance patterns, and current prevalent phenotypes of healthcare-associated MRSA. This knowledge can aid clinicians in improving the antimicrobial stewardship program by adapting appropriate guidelines for the proper use of MRSA antibacterial agents.
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Affiliation(s)
- D Pignataro
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - F Foglia
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - M T Della Rocca
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - C Melardo
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - B Santella
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - V Folliero
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - S Shinde
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - P C Pafundi
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - F C Sasso
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - M R Iovene
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - M Galdiero
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli" , Naples, Italy
| | - G Boccia
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno , Baronissi (SA), Italy
| | - G Franci
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno , Baronissi (SA), Italy
| | - E Finamore
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy
| | - M Galdiero
- Section of Microbiology and Virology, University Hospital "Luigi Vanvitelli" of Naples , Naples, Italy.,Department of Experimental Medicine, University of Campania "Luigi Vanvitelli" , Naples, Italy
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6
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Foglia F, Clancy AJ, Berry-Gair J, Lisowska K, Wilding MC, Suter TM, Miller TS, Smith K, Demmel F, Appel M, Sakai VG, Sella A, Howard CA, Tyagi M, Corà F, McMillan PF. Aquaporin-like water transport in nanoporous crystalline layered carbon nitride. Sci Adv 2020; 6:eabb6011. [PMID: 32978165 PMCID: PMC7518864 DOI: 10.1126/sciadv.abb6011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Designing next-generation fuel cell and filtration devices requires the development of nanoporous materials that allow rapid and reversible uptake and directed transport of water molecules. Here, we combine neutron spectroscopy and first-principles calculations to demonstrate rapid transport of molecular H2O through nanometer-sized voids ordered within the layers of crystalline carbon nitride with a polytriazine imide structure. The transport mechanism involves a sequence of molecular orientation reversals directed by hydrogen-bonding interactions as the neutral molecules traverse the interlayer gap and pass through the intralayer voids that show similarities with the transport of water through transmembrane aquaporin channels in biological systems. The results suggest that nanoporous layered carbon nitrides can be useful for developing high-performance membranes.
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Affiliation(s)
- Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Adam J Clancy
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Jasper Berry-Gair
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Karolina Lisowska
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Martin C Wilding
- University of Manchester at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Theo M Suter
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Keenan Smith
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Franz Demmel
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton OX11 0QX, UK
| | - Markus Appel
- Institut Laue Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble CEDEX 9, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton OX11 0QX, UK
| | - Andrea Sella
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Christopher A Howard
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Madhusudan Tyagi
- NIST Center for Neutron Research (NCNR), National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Furio Corà
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK.
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7
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Beddoes C, Gooris GS, Foglia F, Ahmadi D, Barlow DJ, Lawrence MJ, Demé B, Bouwstra JA. Arrangement of Ceramides in the Skin: Sphingosine Chains Localize at a Single Position in Stratum Corneum Lipid Matrix Models. Langmuir 2020; 36:10270-10278. [PMID: 32816488 PMCID: PMC7498151 DOI: 10.1021/acs.langmuir.0c01992] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Understanding the structure of the stratum corneum (SC) is essential to understand the skin barrier process. The long periodicity phase (LPP) is a unique trilayer lamellar structure located in the SC. Adjustments in the composition of the lipid matrix, as in many skin abnormalities, can have severe effects on the lipid organization and barrier function. Although the location of individual lipid subclasses has been identified, the lipid conformation at these locations remains uncertain. Contrast variation experiments via small-angle neutron diffraction were used to investigate the conformation of ceramide (CER) N-(tetracosanoyl)-sphingosine (NS) within both simplistic and porcine mimicking LPP models. To identify the lipid conformation of the twin chain CER NS, the chains were individually deuterated, and their scattering length profiles were calculated to identify their locations in the LPP unit cell. In the repeating trilayer unit of the LPP, the acyl chain of CER NS was located in the central and outer layers, while the sphingosine chain was located exclusively in the middle of the outer layers. Thus, for the CER NS with the acyl chain in the central layer, this demonstrates an extended conformation. Electron density distribution profiles identified that the lipid structure remains consistent regardless of the lipid's lateral packing phase, this may be partially due to the anchoring of the extended CER NS. The presented results provide a more detailed insight on the internal arrangement of the LPP lipids and how they are expected to be arranged in healthy skin.
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Affiliation(s)
- Charlotte
M. Beddoes
- Division
of BioTherapeutics, Leiden Academic Centre for Drug Research, University of Leiden, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Gert S. Gooris
- Division
of BioTherapeutics, Leiden Academic Centre for Drug Research, University of Leiden, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Fabrizia Foglia
- Chemistry
Department, Christopher Ingold Laboratories, University College London, London WC1H 0AJ, United Kingdom
| | - Delaram Ahmadi
- Pharmaceutical
Science Division, King’s College
London, London WC2R 2LS, United Kingdom
| | - David J. Barlow
- Pharmaceutical
Science Division, King’s College
London, London WC2R 2LS, United Kingdom
| | - M. Jayne Lawrence
- Division
of Pharmacy and Optometry, Manchester University, Manchester M13 9PL, United Kingdom
| | - Bruno Demé
- Institute
Laue-Langevin, Grenoble 38000, France
| | - Joke A. Bouwstra
- Division
of BioTherapeutics, Leiden Academic Centre for Drug Research, University of Leiden, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- . Tel: 00 31 71 527 4208. Fax: 00 31 71 527 4565
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8
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Ahmadi D, Mahmoudi N, Li P, Ma K, Doutch J, Foglia F, Heenan RK, Barlow D, Lawrence MJ. Revealing the Hidden Details of Nanostructure in a Pharmaceutical Cream. Sci Rep 2020; 10:4082. [PMID: 32139812 PMCID: PMC7058068 DOI: 10.1038/s41598-020-61096-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 02/18/2020] [Indexed: 11/14/2022] Open
Abstract
Creams are multi-component semi-solid emulsions that find widespread utility across a wide range of pharmaceutical, cosmetic, and personal care products, and they also feature prominently in veterinary preparations and processed foodstuffs. The internal architectures of these systems, however, have to date been inferred largely through macroscopic and/or indirect experimental observations and so they are not well-characterized at the molecular level. Moreover, while their long-term stability and shelf-life, and their aesthetics and functional utility are critically dependent upon their molecular structure, there is no real understanding yet of the structural mechanisms that underlie the potential destabilizing effects of additives like drugs, anti-oxidants or preservatives, and no structure-based rationale to guide product formulation. In the research reported here we sought to address these deficiencies, making particular use of small-angle neutron scattering and exploiting the device of H/D contrast variation, with complementary studies also performed using bright-field and polarised light microscopy, small-angle and wide-angle X-ray scattering, and steady-state shear rheology measurements. Through the convolved findings from these studies we have secured a finely detailed picture of the molecular structure of creams based on Aqueous Cream BP, and our findings reveal that the structure is quite different from the generic picture of cream structure that is widely accepted and reproduced in textbooks.
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Affiliation(s)
- Delaram Ahmadi
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK
| | - Najet Mahmoudi
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - Peixun Li
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - Kun Ma
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - James Doutch
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratories, University College London, Gordon Street, London, WC1H 0AJ, UK
| | - Richard K Heenan
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - David Barlow
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK.
- Division of Pharmacy & Optometry, Stopford Building, University of Manchester, 99 Oxford Road, Manchester, M13 9PG, UK.
| | - M Jayne Lawrence
- Division of Pharmacy & Optometry, Stopford Building, University of Manchester, 99 Oxford Road, Manchester, M13 9PG, UK.
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9
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Foglia F, Hazael R, Meersman F, Wilding MC, Sakai VG, Rogers S, Bove LE, Koza MM, Moulin M, Haertlein M, Forsyth VT, McMillan PF. In Vivo Water Dynamics in Shewanella oneidensis Bacteria at High Pressure. Sci Rep 2019; 9:8716. [PMID: 31213614 PMCID: PMC6581952 DOI: 10.1038/s41598-019-44704-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/15/2019] [Indexed: 11/10/2022] Open
Abstract
Following observations of survival of microbes and other life forms in deep subsurface environments it is necessary to understand their biological functioning under high pressure conditions. Key aspects of biochemical reactions and transport processes within cells are determined by the intracellular water dynamics. We studied water diffusion and rotational relaxation in live Shewanella oneidensis bacteria at pressures up to 500 MPa using quasi-elastic neutron scattering (QENS). The intracellular diffusion exhibits a significantly greater slowdown (by −10–30%) and an increase in rotational relaxation times (+10–40%) compared with water dynamics in the aqueous solutions used to resuspend the bacterial samples. Those results indicate both a pressure-induced viscosity increase and slowdown in ionic/macromolecular transport properties within the cells affecting the rates of metabolic and other biological processes. Our new data support emerging models for intracellular organisation with nanoscale water channels threading between macromolecular regions within a dynamically organized structure rather than a homogenous gel-like cytoplasm.
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Affiliation(s)
- Fabrizia Foglia
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
| | - Rachael Hazael
- Survivability and Advanced Materials group, Centre for Defence Engineering, Cranfield University at the Defence Academy of the UK, Shrivenham, SN6 8LA, UK
| | - Filip Meersman
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.,Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
| | - Martin C Wilding
- Materials Engineering, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| | | | - Sarah Rogers
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, OX11 0QX, UK
| | - Livia E Bove
- Dipartimento di Fisica, Università di Roma "La Sapienza", 00185, Roma, Italy.,Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre et Marie Curie, F-75252, Paris, France
| | - Michael Marek Koza
- Institut Laue Langevin, 6 Rue Jules Horowitz, BP 156, 38042, Grenoble, Cedex, France
| | - Martine Moulin
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042, Grenoble, cedex 9, France
| | - Michael Haertlein
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042, Grenoble, cedex 9, France
| | - V Trevor Forsyth
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042, Grenoble, cedex 9, France.,Faculty of Natural Sciences/ISTM, Keele University, Staffordshire, ST5 5BG, UK
| | - Paul F McMillan
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
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10
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Milione S, Foglia F, Rinaldi M. Comment on "LncRNA 00152 promotes the development of hepatocellular carcinoma by activating JAK2/STAT3 pathway". Eur Rev Med Pharmacol Sci 2019; 23:3149-3150. [PMID: 31081064 DOI: 10.26355/eurrev_201904_17671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- S Milione
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy.
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11
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Abstract
This study reports a general method to calculate dihedral angles (φ and ψ) of a given amino acid sequence, focusing on potential energy and torque moment concepts. By defining these physical measures in relation to the chemical interactions that occur on each single amino acid residue within a peptide, we analyze the folding process as the result of main mechanical forces (MMFs) exerted in the specific amino acid chain of interest. As a proof of concept, Leu-enkephalin was initially used as a model peptide to carry out the theoretical study. Our data show agreement between calculated Leu-enkephalin backbone dihedral angles and the corresponding experimentally determined X-ray values. Hence, we used calcitonin to validate our MMF-based method on a larger peptide, i.e., 32 amino acid residues forming an α-helix. Through a similar approach (although simplified with regard to electrostatic interactions), the calculations for calcitonin also demonstrate a good agreement with experimental values. This study offers new opportunities to analyze peptides' amino acid sequences and to help in the prediction of how they must fold, assisting in the development of new computational techniques in the field.
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Affiliation(s)
- Michele Larocca
- Institute of Pharmaceutical Science , King's College London , Stamford Street , London SE1 9NH , U.K
| | - Fabrizia Foglia
- Institute of Pharmaceutical Science , King's College London , Stamford Street , London SE1 9NH , U.K
| | - Agostino Cilibrizzi
- Institute of Pharmaceutical Science , King's College London , Stamford Street , London SE1 9NH , U.K
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12
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Abstract
We demonstrate nanoscale wrinkling on polydimethylsiloxane (PDMS) at sub-100 nm length scales via a (double) frontal surface oxidation coupled with a mechanical compression. The kinetics of the glassy skin propagation is resolved by neutron and X-ray reflectivity, and atomic force microscopy, combined with mechanical wrinkling experiments to evaluate the resulting pattern formation. In conventional PDMS surface oxidation, the smallest wrinkling patterns attainable have an intrinsic lower wavelength limit due to the coupling of skin formation and front propagation at fixed strain εprestrain, whose maximum is, in turn, set by material failure. However, combining two different oxidative processes, ultra-violet ozonolysis followed by air plasma exposure, we break this limit by fabricating trilayer laminates with excellent interfacial properties and a sequence of moduli and layer thicknesses able to trivially reduce the surface topography to sub-100 nm dimensions. This method provides a powerful, yet simple, non-lithographic approach to extend surface patterning from visible to the deep UV range.
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Affiliation(s)
- Manuela Nania
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
| | - Fabrizia Foglia
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
| | - Omar K Matar
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
| | - João T Cabral
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
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13
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Foglia F, Hazael R, Simeoni GG, Appavou MS, Moulin M, Haertlein M, Trevor Forsyth V, Seydel T, Daniel I, Meersman F, McMillan PF. Water Dynamics in Shewanella oneidensis at Ambient and High Pressure using Quasi-Elastic Neutron Scattering. Sci Rep 2016; 6:18862. [PMID: 26738409 PMCID: PMC4703977 DOI: 10.1038/srep18862] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/27/2015] [Indexed: 01/22/2023] Open
Abstract
Quasielastic neutron scattering (QENS) is an ideal technique for studying water transport and relaxation dynamics at pico- to nanosecond timescales and at length scales relevant to cellular dimensions. Studies of high pressure dynamic effects in live organisms are needed to understand Earth's deep biosphere and biotechnology applications. Here we applied QENS to study water transport in Shewanella oneidensis at ambient (0.1 MPa) and high (200 MPa) pressure using H/D isotopic contrast experiments for normal and perdeuterated bacteria and buffer solutions to distinguish intracellular and transmembrane processes. The results indicate that intracellular water dynamics are comparable with bulk diffusion rates in aqueous fluids at ambient conditions but a significant reduction occurs in high pressure mobility. We interpret this as due to enhanced interactions with macromolecules in the nanoconfined environment. Overall diffusion rates across the cell envelope also occur at similar rates but unexpected narrowing of the QENS signal appears between momentum transfer values Q = 0.7-1.1 Å(-1) corresponding to real space dimensions of 6-9 Å. The relaxation time increase can be explained by correlated dynamics of molecules passing through Aquaporin water transport complexes located within the inner or outer membrane structures.
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Affiliation(s)
- Fabrizia Foglia
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, UK
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Rachael Hazael
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Giovanna G. Simeoni
- Heinz Maier-Leibnitz Zentrum (MLZ) and Physics Department, Technisches Universität München, Lichtenbergstrasse 1, D-85748 Garching, Germany
| | - Marie-Sousai Appavou
- Jülich Center for Neutron Sciences at MLZ, Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, D-85748 Garching, Germany
| | - Martine Moulin
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble cedex 9, France
| | - Michael Haertlein
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble cedex 9, France
| | - V. Trevor Forsyth
- Life Sciences Group, Carl-Ivar Brändén Building, Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble cedex 9, France
- Faculty of Natural Sciences/ISTM, Keele University, Staffordshire ST5 5BG, UK
| | - Tilo Seydel
- Science Division, Institut Laue-Langevin, CS 20156, 71 avenue des Martyrs, 38042 Grenoble cedex 9, France
| | - Isabelle Daniel
- Laboratoire de Géologie de Lyon, UMR 5276, Université Lyon 1-ENS de Lyon-CNRS, 2 rue Raphaël Dubois, 69622 Villeurbanne, France
| | - Filip Meersman
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, UK
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Paul F. McMillan
- Chemistry Department, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, UK
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14
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Foglia F, Lawrence M, Barlow D. Studies of model biological and bio-mimetic membrane structure: Reflectivity vs diffraction, a critical comparison. Curr Opin Colloid Interface Sci 2015. [DOI: 10.1016/j.cocis.2015.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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15
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Foglia F, Rogers SE, Webster JRP, Akeroyd FA, Gascoyne KF, Lawrence MJ, Barlow DJ. Neutron Scattering Studies of the Effects of Formulating Amphotericin B with Cholesteryl Sulfate on the Drug's Interactions with Phospholipid and Phospholipid-Sterol Membranes. Langmuir 2015; 31:8042-8051. [PMID: 26139630 DOI: 10.1021/acs.langmuir.5b01365] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Langmuir surface pressure, small-angle neutron scattering (SANS), and neutron reflectivity (NR) studies have been performed to determine how formulation of the antifungal drug amphotericin B (AmB), with sodium cholesteryl sulfate (SCS)-as in Amphotec-affects its interactions with ergosterol-containing (model fungal cell) and cholesterol-containing (model mammalian cell) membranes. The effects of mixing AmB in 1:1 molar ratio with cholesteryl sulfate (yielding AmB-SCS micelles) are compared against those of free AmB, using monolayers and bilayers formed from palmitoyloleoylphosphatidylcholine (POPC) in the absence and presence of 30 mol % ergosterol or cholesterol, in all cases employing a 1:0.05 molar ratio of lipid:AmB. Analyses of the (bilayer) SANS and (monolayer) NR data indicate that the equilibrium changes in membrane structure induced in sterol-free and sterol-containing membranes are the same for free AmB and AmB-SCS. Stopped-flow SANS experiments, however, reveal that the structural changes to vesicle membranes occur far more rapidly following exposure to AmB-SCS vs free drug, with the kinetics of these changes varying with membrane composition. With POPC vesicles, the structural changes induced by AmB-SCS become apparent only after several minutes, and equilibrium is reached after ∼30 min. The corresponding onset of changes in POPC-ergosterol and POPC-cholesterol vesicles, however, occurs within ∼5 s, with equilibrium reached after 10 and 120 s, respectively. The rate of insertion of AmB into POPC-sterol membranes is thus increased through formulation as AmB-SCS. Moreover, the differences in monolayer surface pressure and SANS structure-change equilibration times suggest significant rearrangement of AmB within these membranes following insertion. The reduced times to equilibrium for the POPC-ergosterol vs POPC-cholesterol systems are consistent with the known differences in affinity of AmB for these two sterols, and the reduced time to equilibrium for AmB-SCS interaction with POPC-ergosterol membranes vs that for free AmB is consistent with the reduced host toxicity of Amphotec.
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Affiliation(s)
- F Foglia
- †Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | | | | | | | | | - M J Lawrence
- †Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - D J Barlow
- †Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
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16
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Leguy AMA, Frost JM, McMahon AP, Sakai VG, Kochelmann W, Law C, Li X, Foglia F, Walsh A, O'Regan BC, Nelson J, Cabral JT, Barnes PRF. The dynamics of methylammonium ions in hybrid organic-inorganic perovskite solar cells. Nat Commun 2015; 6:7124. [PMID: 26023041 PMCID: PMC4458867 DOI: 10.1038/ncomms8124] [Citation(s) in RCA: 229] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/07/2015] [Indexed: 12/23/2022] Open
Abstract
Methylammonium lead iodide perovskite can make high-efficiency solar cells, which also show an unexplained photocurrent hysteresis dependent on the device-poling history. Here we report quasielastic neutron scattering measurements showing that dipolar CH3NH3+ ions reorientate between the faces, corners or edges of the pseudo-cubic lattice cages in CH3NH3PbI3 crystals with a room temperature residence time of ∼14 ps. Free rotation, π-flips and ionic diffusion are ruled out within a 1–200-ps time window. Monte Carlo simulations of interacting CH3NH3+ dipoles realigning within a 3D lattice suggest that the scattering measurements may be explained by the stabilization of CH3NH3+ in either antiferroelectric or ferroelectric domains. Collective realignment of CH3NH3+ to screen a device's built-in potential could reduce photovoltaic performance. However, we estimate the timescale for a domain wall to traverse a typical device to be ∼0.1–1 ms, faster than most observed hysteresis. Hysteresis often exists in the characterization of methylammonium lead halide-based solar cells, but is not well understood. Here, the authors use quasielastic neutron scattering to study the dynamics of dipolar organic cations and shed light on the hysteresis behaviour.
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Affiliation(s)
| | - Jarvist Moore Frost
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Andrew P McMahon
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | | | - W Kochelmann
- Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, UK
| | - ChunHung Law
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Xiaoe Li
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Fabrizia Foglia
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Aron Walsh
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Brian C O'Regan
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Jenny Nelson
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | - João T Cabral
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Piers R F Barnes
- Department of Physics, Imperial College London, London SW7 2AZ, UK
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17
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Hazael R, Foglia F, Kardzhaliyska L, Daniel I, Meersman F, McMillan P. Laboratory investigation of high pressure survival in Shewanella oneidensis MR-1 into the gigapascal pressure range. Front Microbiol 2014; 5:612. [PMID: 25452750 PMCID: PMC4233909 DOI: 10.3389/fmicb.2014.00612] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/28/2014] [Indexed: 11/13/2022] Open
Abstract
The survival of Shewanella oneidensis MR-1 at up to 1500 MPa was investigated by laboratory studies involving exposure to high pressure followed by evaluation of survivors as the number (N) of colony forming units (CFU) that could be cultured following recovery to ambient conditions. Exposing the wild type (WT) bacteria to 250 MPa resulted in only a minor (0.7 log N units) drop in survival compared with the initial concentration of 108 cells/ml. Raising the pressure to above 500 MPa caused a large reduction in the number of viable cells observed following recovery to ambient pressure. Additional pressure increase caused a further decrease in survivability, with approximately 102 CFU/ml recorded following exposure to 1000 MPa (1 GPa) and 1.5 GPa. Pressurizing samples from colonies resuscitated from survivors that had been previously exposed to high pressure resulted in substantially greater survivor counts. Experiments were carried out to examine potential interactions between pressure and temperature variables in determining bacterial survival. One generation of survivors previously exposed to 1 GPa was compared with WT samples to investigate survival between 37 and 8°C. The results did not reveal any coupling between acquired high pressure resistance and temperature effects on growth.
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Affiliation(s)
- Rachael Hazael
- Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK
| | - Fabrizia Foglia
- Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK
| | - Liya Kardzhaliyska
- Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK
| | - Isabelle Daniel
- Laboratoire de Géologie de Lyon, UMR 5276 CNRS, ENS de Lyon and Université Claude Bernard Lyon 1 - Université de Lyon Lyon, France
| | - Filip Meersman
- Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK ; Biomolecular and Analytical Mass Spectrometry group, Department of Chemistry, University of Antwerp Antwerpen, Belgium
| | - Paul McMillan
- Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK
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18
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Abstract
Langmuir isotherm, neutron reflectivity, and Brewster angle microscopy experiments have been performed to study the interaction of amphotericin B (AmB) with monolayers prepared from 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and mixtures of this lipid with cholesterol or ergosterol to mimic mammalian and fungal cell membranes, respectively. Isotherm data show that AmB causes a more pronounced change in surface pressure in the POPC/ergosterol system than in the POPC and POPC/cholesterol systems, and its interaction with the POPC/ergosterol monolayer is also more rapid than with the POPC and POPC/cholesterol monolayers. Brewster angle microscopy shows that, in interaction with POPC monolayers, AmB causes the formation of small domains which shrink and disappear within a few minutes. The drug also causes domain formation in the POPC/cholesterol and POPC/ergosterol monolayers; in the former case, these are formed more slowly than is seen with the POPC monolayers and are ultimately much smaller; in the latter case, they are formed rather more quickly and are more heterogeneous in size. Neutron reflectivity data show that the changes in monolayer structure following interaction with AmB are the same for all three systems studied: the data are consistent with the drug inserting into the monolayers with its macrocyclic ring intercalated among the lipid acyl chains and sterol ring systems, with its mycosamine moiety colocalizing with the sterol hydroxyl and POPC head groups. On the basis of these studies, it is concluded that AmB inserts in a similar manner into POPC, POPC/cholesterol, and POPC/ergosterol monolayers but does so with differing kinetics and with the formation of quite different in-plane structures. The more rapid time scale for interaction of the drug with the POPC/ergosterol monolayer, its more pronounced effect on monolayer surface pressure, and its more marked changes as regards domain formation are all consistent with the drug's selectivity for fungal vs mammalian cell membranes.
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Affiliation(s)
- F Foglia
- Institute of Pharmaceutical Science, King's College London , Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
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19
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Foglia F, Lawrence MJ, Demė B, Fragneto G, Barlow D. Neutron diffraction studies of the interaction between amphotericin B and lipid-sterol model membranes. Sci Rep 2012; 2:778. [PMID: 23110248 PMCID: PMC3482691 DOI: 10.1038/srep00778] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/18/2012] [Indexed: 12/13/2022] Open
Abstract
Over the last 50 years or so, amphotericin has been widely employed in treating life-threatening systemic fungal infections. Its usefulness in the clinic, however, has always been circumscribed by its dose-limiting side-effects, and it is also now compromised by an increasing incidence of pathogen resistance. Combating these problems through development of new anti-fungal agents requires detailed knowledge of the drug's molecular mechanism, but unfortunately this is far from clear. Neutron diffraction studies of the drug's incorporation within lipid-sterol membranes have here been performed to shed light on this problem. The drug is shown to disturb the structures of both fungal and mammalian membranes, and co-localises with the membrane sterols in a manner consistent with trans-membrane pore formation. The differences seen in the membrane lipid ordering and in the distributions of the drug-ergosterol and drug-cholesterol complexes within the membranes are consistent with the drug's selectivity for fungal vs. human cells.
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Affiliation(s)
- Fabrizia Foglia
- Institute of Pharmaceutical Science, King's College London, London, UK
| | - M. Jayne Lawrence
- Institute of Pharmaceutical Science, King's College London, London, UK
| | - Bruno Demė
- Institut de Laue Langevin, Grenoble, France
| | | | - David Barlow
- Institute of Pharmaceutical Science, King's College London, London, UK
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20
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Backhouse MR, Vinall KA, Redmond A, Helliwell P, Keenan AM, Dale RM, Thomas A, Aronson D, Turner-Cobb J, Sengupta R, France B, Hill I, Flurey CA, Morris M, Pollock J, Hughes R, Richards P, Hewlett S, Ryan S, Lille K, Adams J, Haq I, McArthur M, Goodacre L, Birt L, Wilson O, Kirwan J, Dures E, Quest E, Hewlett S, Rajak R, Thomas T, Lawson T, Petford S, Hale E, Kitas GD, Ryan S, Gooberman-Hill R, Jinks C, Dziedzic K, Boucas SB, Hislop K, Rhodes C, Adams J, Ali F, Jinks C, Ong BN, Backhouse MR, White D, Hensor E, Keenan AM, Helliwell P, Redmond A, Ferguson AM, Douiri A, Scott DL, Lempp H, Halls S, Law RJ, Jones J, Markland D, Maddison P, Thom J, Law RJ, Thom JM, Maddison P, Breslin A, Kraus A, Gordhan C, Dennis S, Connor J, Chowdhary B, Lottay N, Juneja P, Bacon PA, Isaacs D, Jack J, Keller M, Tibble J, Haq I, Hammond A, Gill R, Tyson S, Tennant A, Nordenskiold U, Pease EE, Pease CT, Trehane A, Rahmeh F, Cornell P, Westlake SL, Rose K, Alber CF, Watson L, Stratton R, Lazarus M, McNeilly NE, Waterfield J, Hurley M, Greenwood J, Clayton AM, Lynch M, Clewes A, Dawson J, Abernethy V, Griffiths AE, Chamberlain VA, McLoughlin Y, Campbell S, Hayes J, Moffat C, McKenna F, Shah P, Rajak R, Williams A, Rhys-Dillon C, Goodfellow R, Martin JC, Rajak R, Bari F, Hughes G, Thomas E, Baker S, Collins D, Price E, Williamson L, Dunkley L, Youll MJ, Rodziewicz M, Reynolds JA, Berry J, Pavey C, Hyrich K, Gorodkin R, Wilkinson K, Bruce I, Barton A, Silman A, Ho P, Cornell T, Westlake SL, Richards S, Holmes A, Parker S, Smith H, Briggs N, Arthanari S, Nisar M, Thwaites C, Ryan S, Kamath S, Price S, Robinson SM, Walker D, Coop H, Al-Allaf W, Baker S, Williamson L, Price E, Collins D, Charleton RC, Griffiths B, Edwards EA, Partlett R, Martin K, Tarzi M, Panthakalam S, Freeman T, Ainley L, Turner M, Hughes L, Russell B, Jenkins S, Done J, Young A, Jones T, Gaywood IC, Pande I, Pradere MJ, Bhaduri M, Smith A, Cook H, Abraham S, Ngcozana T, Denton CP, Parker L, Black CM, Ong V, Thompson N, White C, Duddy M, Jobanputra P, Bacon P, Smith J, Richardson A, Giancola G, Soh V, Spencer S, Greenhalgh A, Hanson M, De Lord D, Lloyd M, Wong H, Wren D, Grover B, Hall J, Neville C, Alton P, Kelly S, Bombardieri M, Humby F, Ng N, Di Cicco M, Hands R, Epis O, Filer A, Buckley C, McInnes I, Taylor P, Pitzalis C, Freeston J, Conaghan P, Grainger A, O'Connor PJ, Evans R, Emery P, Hodgson R, Emery P, Fleischmann R, Han C, van der Heijde D, Conaghan P, Xu W, Hsia E, Kavanaugh A, Gladman D, Chattopadhyay C, Beutler A, Han C, Zayat AS, Conaghan P, Freeston J, Hensor E, Ellegard K, Terslev L, Emery P, Wakefield RJ, Ciurtin C, Leandro M, Dey D, Nandagudi A, Giles I, Shipley M, Morris V, Ioannou J, Ehrenstein M, Sen D, Chan M, Quinlan TM, Brophy R, Mewar D, Patel D, Wilby MJ, Pellegrini V, Eyes B, Crooks D, Anderson M, Ball E, McKeeman H, Burns J, Yau WH, Moore O, Foo J, Benson C, Patterson C, Wright G, Taggart A, Drew S, Tanner L, Sanyal K, Bourke BE, Lloyd M, Alston C, Baqai C, Chard M, Sandhu V, Neville C, Jordan K, Munns C, Zouita L, Shattles W, Davies U, Makadsi R, Griffith S, Kiely PD, Ciurtin C, Dimofte I, Dabu M, Dabu B, Dobarro D, Schreiber BE, Warrell C, Handler C, Coghlan G, Denton C, Ishorari J, Bunn C, Beynon H, Denton CP, Stratton R, George Malal JJ, Boton-Maggs B, Leung A, Farewell D, Choy E, Gullick NJ, Young A, Choy EH, Scott DL, Wincup C, Fisher B, Charles P, Taylor P, Gullick NJ, Pollard LC, Kirkham BW, Scott DL, Ma MH, Ramanujan S, Cavet G, Haney D, Kingsley GH, Scott D, Cope A, Singh A, Wilson J, Isaacs A, Wing C, McLaughlin M, Penn H, Genovese MC, Sebba A, Rubbert-Roth A, Scali J, Zilberstein M, Thompson L, Van Vollenhoven R, De Benedetti F, Brunner H, Allen R, Brown D, Chaitow J, Pardeo M, Espada G, Flato B, Horneff G, Devlin C, Kenwright A, Schneider R, Woo P, Martini A, Lovell D, Ruperto N, John H, Hale ED, Treharne GJ, Kitas GD, Carroll D, Mercer L, Low A, Galloway J, Watson K, Lunt M, Symmons D, Hyrich K, Low A, Mercer L, Galloway J, Davies R, Watson K, Lunt M, Dixon W, Hyrich K, Symmons D, Balarajah S, Sandhu A, Ariyo M, Rankin E, Sandoo A, van Zanten JJV, Toms TE, Carroll D, Kitas GD, Sandoo A, Smith JP, Kitas GD, Malik S, Toberty E, Thalayasingam N, Hamilton J, Kelly C, Puntis D, Malik S, Hamilton J, Saravanan V, Rynne M, Heycock C, Kelly C, Rajak R, Goodfellow R, Rhys-Dillon C, Winter R, Wardle P, Martin JC, Toms T, Sandoo A, Smith J, Cadman S, Nightingale P, Kitas G, Alhusain AZ, Verstappen SM, Mirjafari H, Lunt M, Charlton-Menys V, Bunn D, Symmons D, Durrington P, Bruce I, Cooney JK, Thom JM, Moore JP, Lemmey A, Jones JG, Maddison PJ, Ahmad YA, Ahmed TJ, Leone F, Kiely PD, Browne HK, Rhys-Dillon C, Wig S, Chevance A, Moore T, Manning J, Vail A, Herrick AL, Derrett-Smith E, Hoyles R, Moinzadeh P, Chighizola C, Khan K, Ong V, Abraham D, Denton CP, Schreiber BE, Dobarro D, Warrell CE, Handler C, Denton CP, Coghlan G, Sykes R, Muir L, Ennis H, Herrick AL, Shiwen X, Thompson K, Khan K, Liu S, Denton CP, Leask A, Abraham DJ, Strickland G, Pauling J, Betteridge Z, Dunphy J, Owen P, McHugh N, Abignano G, Cuomo G, Buch MH, Rosenberg WM, Valentini G, Emery P, Del Galdo F, Jenkins J, Pauling JD, McHugh N, Khan K, Shiwen X, Abraham D, Denton CP, Ong V, Moinzadeh P, Howell K, Ong V, Nihtyanova S, Denton CP, Moinzadeh P, Fonseca C, Khan K, Abraham D, Ong V, Denton CP, Malaviya AP, Hadjinicolaou AV, Nisar MK, Ruddlesden M, Furlong A, Baker S, Hall FC, Hadjinicolaou AV, Malaviya AP, Nisar MK, Ruddlesden M, Raut-Roy D, Furlong A, Baker S, Hall FC, Peluso R, Dario Di Minno MN, Iervolino S, Costa L, Atteno M, Lofrano M, Soscia E, Castiglione F, Foglia F, Scarpa R, Wallis D, Thomas A, Hill I, France B, Sengupta R, Dougados M, Keystone E, Heckaman M, Mease P, Landewe R, Nguyen D, Heckaman M, Mease P, Winfield RA, Dyke C, Clemence M, Mackay K, Haywood KL, Packham J, Jordan KP, Davies H, Brophy S, Irvine E, Cooksey R, Dennis MS, Siebert S, Kingsley GH, Ibrahim F, Scott DL, Kavanaugh A, McInnes I, Chattopadhyay C, Krueger G, Gladman D, Beutler A, Gathany T, Mudivarthy S, Mack M, Tandon N, Han C, Mease P, McInnes I, Sieper J, Braun J, Emery P, van der Heijde D, Isaacs J, Dahmen G, Wollenhaupt J, Schulze-Koops H, Gsteiger S, Bertolino A, Hueber W, Tak PP, Cohen CJ, Karaderi T, Pointon JJ, Wordsworth BP, Cooksey R, Davies H, Dennis MS, Siebert S, Brophy S, Keidel S, Pointon JJ, Farrar C, Karaderi T, Appleton LH, Wordsworth BP, Adshead R, Tahir H, Greenwood M, Donnelly SP, Wajed J, Kirkham B. BHPR research: qualitative * 1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis. Rheumatology (Oxford) 2012. [DOI: 10.1093/rheumatology/kes110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Iervolino S, Lofrano M, Di Minno M, Foglia F, Scarpa R, Peluso R. IgA deficiency evidence after anti-TNF-α treatment in a psoriatic arthritis patient: case report. Reumatismo 2012; 64:40-3. [DOI: 10.4081/reumatismo.2012.40] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/26/2012] [Accepted: 01/26/2012] [Indexed: 11/23/2022] Open
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Dabkowska AP, Foglia F, Lawrence MJ, Lorenz CD, McLain SE. On the solvation structure of dimethylsulfoxide/water around the phosphatidylcholine head group in solution. J Chem Phys 2011; 135:225105. [DOI: 10.1063/1.3658382] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Foglia F, Barlow DJ, Szoka FC, Huang Z, Rogers SE, Lawrence MJ. Structural studies of the monolayers and bilayers formed by a novel cholesterol-phospholipid chimera. Langmuir 2011; 27:8275-8281. [PMID: 21634402 DOI: 10.1021/la200739y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Langmuir isotherm, neutron reflectivity, and small angle neutron scattering studies have been conducted to characterize the monolayers and vesicular bilayers formed by a novel chimeric phospholipid, ChemPPC, that incorporates a cholesteryl moeity and a C-16 aliphatic chain, each covalently linked via a glycerol backbone to phosphatidylcholine. The structures of the ChemPPC monolayers and bilayers are compared against those formed from pure dipalmitoylphoshatidylcholine (DPPC) and those formed from a 60:40 mol % mixture of DPPC and cholesterol. In accord with previous findings showing that very similar macroscopic properties were exhibited by ChemPPC and 60:40 mol % DPPC/cholesterol vesicles, it is found here that the chimeric lipid and lipid/sterol mixture have very similar monolayer structures (each having a monolayer thickness of ∼26 Å), and they also form vesicles with similar lamellar structure, each having a bilayer thickness of ∼50 Å and exhibiting a repeat spacing of ∼65 Å. The interfacial area of ChemPPC, however, is around 10 Å(2) greater than that of the combined DPPC/cholesterol unit in the mixed lipid monolayer (viz., 57 ± 1 vs 46 ± 1 Å(2), at 35 mN·m(-1)), and this difference in area is attributed to the succinyl linkage which joins the ChemPPC steroid and glyceryl moieties. The larger area of the ChemPPC is reflected in a slightly thicker monolayer solvent distribution width (9.5 vs 9 Å for the DPPC/cholesterol system) and by a marginal increase in the level of lipid headgroup hydration (16 vs 13 H(2)O per lipid, at 35 mN·m(-1)).
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Affiliation(s)
- F Foglia
- Pharmaceutical Science Division, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
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Foglia F, Drake A, Terry A, Rogers S, Lawrence M, Barlow D. Small-angle neutron scattering studies of the effects of amphotericin B on phospholipid and phospholipid–sterol membrane structure. Biochimica et Biophysica Acta (BBA) - Biomembranes 2011; 1808:1574-80. [DOI: 10.1016/j.bbamem.2011.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 01/18/2011] [Accepted: 02/09/2011] [Indexed: 11/26/2022]
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Abstract
The hydration of the phosphocholine headgroup in 1,2-dipropionyl-sn-glycero-3-phosphocholine (C(3)-PC) in solution has been determined by using neutron diffraction enhanced with isotopic substitution in combination with computer simulation techniques. The atomic scale hydration structure around this head group shows that both the -N(CH(3))(3) and -CH(2) portions of the choline headgroup are strongly associated with water, through a unique hydrogen bonding regime, where specifically a hydrogen bond from the C-H group to water and a strong association between the water oxygen and N(+) atom in solution have both been observed. In addition, both PO(4) oxygens (P=O) and C=O oxygens are oversaturated when compared to bulk water in that the average number of hydrogen bonds from water to both X=O oxygens is about 2.5 for each group. That water binds strongly to the glycerol groups and is suggestive that water may bind to these groups when phosophotidylcholine is embedded in a membrane bilayer.
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Affiliation(s)
- Fabrizia Foglia
- Department of Pharmaceutical Sciences, King's College London, London SE1 9NH, United Kingdom
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Foglia F, Mandrich L, Pezzullo M, Graziano G, Barone G, Rossi M, Manco G, Del Vecchio P. Role of the N-terminal region for the conformational stability of esterase 2 from Alicyclobacillus acidocaldarius. Biophys Chem 2007; 127:113-22. [PMID: 17289253 DOI: 10.1016/j.bpc.2007.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 01/10/2007] [Accepted: 01/10/2007] [Indexed: 11/16/2022]
Abstract
In order to clarify the role played by the N-terminal region for the conformational stability of the thermophilic esterase 2 (EST2) from Alicyclobacillus acidocaldarius, two mutant forms have been investigated: a variant obtained by deleting the first 35 residues at the N-terminus (EST2-36del), and a variant obtained by mutating Lys102 to Gln (K102Q) to perturb the N-terminus by destroying the salt bridge E43-K102. The temperature- and denaturant-induced unfolding of EST2 and the two mutant forms have been studied by means of circular dichroism (CD), differential scanning calorimetry (DSC) and fluorescence measurements. In line with its thermophilic origin, the denaturation temperature of EST2 is high: T(d)=91 degrees C and 86 degrees C if detected by recording the CD signal at 222 nm and 290 nm, respectively. This difference suggests that the thermal denaturation process, even though reversible, is more complex than a two-state Nright arrow over left arrowD transition. The non-two-state behaviour is more pronounced in the case of the two mutant forms. The complex DSC profiles of EST2 and both mutant forms have been analysed by means of a deconvolution procedure. The thermodynamic parameters characterizing the two transitions obtained in the case of EST2 are: T(d,1)=81 degrees C, Delta(d)H(1)=440 kJ mol(-1), Delta(d)C(p,1)=7 kJ K(-1)mol(-1), T(d,2)=86 degrees C, Delta(d)H(2)=710 kJ mol(-1), and Delta(d)C(p,2)=9 kJ K(-1)mol(-1). The first transition occurs at lower temperatures in the two mutant forms, whereas the second transition is always centred at 86 degrees C. The results indicate that EST2 possesses two structural domains whose coupling is tight in the wild-type protein, but markedly weakens in the two mutant forms as a consequence of the perturbations in the N-terminal region.
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Affiliation(s)
- Fabrizia Foglia
- Dipartimento di Chimica, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
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Kowall T, Foglia F, Helm L, Merbach AE. Molecular Dynamics Simulation Study of Lanthanide Ions Ln3+ in Aqueous Solution Including Water Polarization. Change in Coordination Number from 9 to 8 along the Series. J Am Chem Soc 2002. [DOI: 10.1021/ja00118a015] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kowall T, Foglia F, Helm L, Merbach AE. Molecular Dynamics Simulation Study of Lanthanide Ions Ln3+ in Aqueous Solution. Analysis of the Structure of the First Hydration Shell and of the Origin of Symmetry Fluctuations. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100035a007] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bleuzen A, Foglia F, Furet E, Helm L, Merbach AE, Weber J. Second Coordination Shell Water Exchange Rate and Mechanism: Experiments and Modeling on Hexaaquachromium(III). J Am Chem Soc 1996. [DOI: 10.1021/ja9613116] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gentile S, Porcellini M, Leo C, Foglia F. [Influence of phenobarbital on hyperbilirubinemia caused by nicotinic acid and rifamycin--SV in healthy subjects]. Boll Soc Ital Biol Sper 1979; 55:2184-9. [PMID: 548051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ten healthy subjects have been given before and after treatment with phenobarbital the following intravenous charges: a) nicotinic acid; b) rifamicyn-SV; c) simultaneous administration of the two drugs. Along with confirmatory evidence of the wellknown increase in bilirubinaemia (prevalently unconjugated), we have observed phenobarbital to attempts partially yet significantly that effect. On the base of direct experience on rat liver, we hypothise phenobarbital to increase the pool of the Y protein carrying cholephilic organic anions into the hepatocytes.
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Gentile S, Porcellini M, Foglia F, Coltorti M. [Mechanisms of detecting organic cholephilic anions in man: comparative studies on plasma depuration of rifamycin-SV. Interference of nicotinic acid and phenobarbital]. Boll Soc Ital Biol Sper 1979; 55:1307-11. [PMID: 508427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We have studied plasmatic half-life of R-SV administered alone and in association with nicotinic acid, before and after treatment with phenobarbital, in 10 normobilirubinaemic subjects and in 10 patients Gilbert's syndrome, used like controls. Ouer results confirm the existence of some alterations of drug-metabolism produced by associated administration of other drugs, in both healthy and hyperbilirubinaemic subjects, and in these one even more.
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Gentile S, Porcellini M, Foglia F, Loguercio C, Coltorti M. [Influence of allopurinol on the half-life of tolbutamide and rifamycin-SV in blood of healthy volunteers]. Boll Soc Ital Biol Sper 1979; 55:345-8. [PMID: 552849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The influence of treatment with allopurinol (5 mg/kg/die for 15 days) on T/2 of tolbutamide and rifomycin-SV intravenously administered, has been studied in 10 healthy volunteers. We have observed reduction of T/2 of tolbutamide and, on the contrary, prolongation of T/2 of rifamycin-SV. Tolbutamide behaviour was unexpected, considering that other Authors had previously found inhibition of metabolic degradation of other drugs metabolized by the microsomal enzymes. We conclude that data concerning the influence of a drug (in our case, allopurinol) on the metabolism of another drug cannot always authorize general deduction and previsions regarding the metabolic interferences on the pharmacokinetics of other substances.
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