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Richard AJ, Ferguson M, Fiss BG, Titi HM, Valdez J, Provatas N, Friščić T, Moores A. In situ study of Au nanoparticle formation in a mechanochemical-aging-based method. Nanoscale Adv 2023; 5:2776-2784. [PMID: 37205288 PMCID: PMC10187004 DOI: 10.1039/d2na00759b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 03/14/2023] [Indexed: 05/21/2023]
Abstract
As we strive to perform chemical transformations in a more sustainable fashion, enabling solid-state reactions through mechanochemistry has emerged as a highly successful approach. Due to the wide-ranging applications of gold nanoparticles (AuNPs), mechanochemical strategies have already been employed for their synthesis. However, the underlying processes surrounding gold salt reduction, nucleation and growth of AuNPs in the solid state are yet to be understood. Here, we present a mechanically activated aging synthesis of AuNPs, through a solid-state Turkevich reaction. Solid reactants are only briefly exposed to input of mechanical energy before being aged statically over a period of six weeks at different temperatures. This system offers an excellent opportunity for an in situ analysis of both reduction and nanoparticle formation processes. During the aging period, the reaction was monitored using a combination of X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy, powder X-ray diffraction and transmission electron microscopy, to gain meaningful insights into the mechanisms of solid-state formation of gold nanoparticles. The acquired data allowed for the establishment of the first kinetic model for solid-state nanoparticle formation.
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Affiliation(s)
- Austin J Richard
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
| | - Michael Ferguson
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
- School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Blaine G Fiss
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
| | - Hatem M Titi
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
| | - Jesus Valdez
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
- Facility for Electron Microscopy Research, McGill University 3640 University Street Montréal Québec H3A0C7 Canada
| | - Nikolas Provatas
- Department of Physics, McGill University 3600 University Street Montréal Québec H3A 2T8 Canada
- McGill High Performance Computing Centre, École de Technologie Supérieure (ETS) 1100 Notre Dame Street West Montréal Québec H3C 1K3 Canada
| | - Tomislav Friščić
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
- School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Audrey Moores
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University 801 Sherbrooke Street West Montréal Québec H3A 0B8 Canada
- Department of Materials Engineering, McGill University 3610 University Street Montréal Québec H3A 0C5 Canada
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2
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He W, Chen C, Liu Y, Tomasino A, Mousavi Masouleh SS, Valdez J, Guner T, Morandotti R, Moores A, Botton GA, Zhou Y, Yurtsever A, Ma D. Imaging Photon-Induced Near-Field Distributions of a Plasmonic, Self-Assembled Vesicle by a Laser-Integrated Electron Microscope. Nano Lett 2023. [PMID: 36995289 DOI: 10.1021/acs.nanolett.2c05096] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Plasmonic polymeric nanoassemblies offer valuable opportunities in photoconversion applications. Localized surface plasmon mechanisms behind such nanoassemblies govern their functionalities under light illumination. However, an in-depth investigation at the single nanoparticle (NP) level is still challenging, especially when the buried interface is involved, due to the availability of suitable techniques. Here, we synthesized an anisotropic heterodimer composed of a self-assembled polymer vesicle (THPG) capped with a single gold NP, enabling an 8-fold enhancement in hydrogen generation compared to the nonplasmonic THPG vesicle. We explored the anisotropic heterodimer at the single particle level by employing advanced transmission electron microscopes, including one equipped with a femtosecond pulsed laser, which allows us to visualize the polarization- and frequency-dependent distribution of the enhanced electric near fields at the vicinity of Au cap and Au-polymer interface. These elaborated fundamental findings may guide designing new hybrid nanostructures tailored for plasmon-related applications.
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Affiliation(s)
- Wanting He
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
| | - Chuanshuang Chen
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Yannan Liu
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Department of Synthetic Materials and Functional Devices, Max-Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Alessandro Tomasino
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
| | | | - Jesus Valdez
- Facility for Electron Microscopy Research (FEMR), McGill University, Montréal, QC H3A 037, Canada
| | - Tugrul Guner
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
| | - Roberto Morandotti
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
| | - Audrey Moores
- Facility for Electron Microscopy Research (FEMR), McGill University, Montréal, QC H3A 037, Canada
| | - Gianluigi A Botton
- Department of Materials Science and Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada
- Canadian Light Source, Saskatoon, SK S7N 2V3, Canada
| | - Yongfeng Zhou
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Aycan Yurtsever
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
| | - Dongling Ma
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Varennes, QC J3X 1P7, Canada
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Ferguson M, Richard AJ, Valdez J, Fiss BG, Titi HM, Provatas N, Friščić T, Moores A. Direct observation by high resolution transmission electron microscopy of gold(III) particle transformation during aging reduction reaction. Faraday Discuss 2023; 241:278-288. [PMID: 36218357 DOI: 10.1039/d2fd00126h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We use a gold nanoparticle synthesis as a model system to study the morphological and compositional changes in gold(III) precursor particles, while reduction is taking place during aging after mechanical activation. Scanning transmission electron microscopy coupled with a high-angle annular dark field detector revealed the nanoscale changes in particle morphology, while electron energy loss spectroscopy mapped the changes in the chemical landscape during the reduction process. Tracking a specific region of interest on the sample grid allowed for comparisons to be made of the same particles across a two day monitoring period. High-angle annular dark field images permitted the visualization of particle size reduction of the gold salt while electron energy loss spectroscopy captured the surprising mobility of the lighter chlorine and sodium ions in a solid matrix during the reduction process. This system offers unique insight into precursor particle reactivity in the solid phase, which is relevant for many mechanochemical and aging-based reactions.
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Affiliation(s)
- Michael Ferguson
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada.
| | - Austin J Richard
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada.
| | - Jesus Valdez
- Facility for Electron Microscopy Research, McGill University, 3640 University Street, Montréal, Québec H3A 0C7, Canada
| | - Blaine G Fiss
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada.
| | - Hatem M Titi
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada.
| | - Nikolas Provatas
- Department of Physics, McGill University, 3600 University Street, Montréal, Québec H3A 2T8, Canada.,McGill High Performance Computing Centre, École de Technologie Supérieure (ETS), 1100 Notre Dame Street West, Montréal, Québec H3C 1K3, Canada
| | - Tomislav Friščić
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada.
| | - Audrey Moores
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada. .,Department of Materials Engineering, McGill University, 3610 University Street, Montréal, Québec H3A 0C5, Canada
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Chen C, Chu G, He W, Liu Y, Dai K, Valdez J, Moores A, Huang P, Wang Z, Jin J, Guan M, Jiang W, Mai Y, Ma D, Wang Y, Zhou Y. A Janus Au-Polymersome Heterostructure with Near-Field Enhancement Effect for Implant-Associated Infection Phototherapy. Adv Mater 2023; 35:e2207950. [PMID: 36300600 DOI: 10.1002/adma.202207950] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Polymer-inorganic hybrid Janus nanoparticles (PI-JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI-JNPs remains challenging. Herein, the construction of a novel Janus Au-porphyrin polymersome (J-AuPPS) heterostructure by a facile one-step photocatalytic synthesis is reported. The near-field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J-AuPPS is achieved to enhance its near-infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improves the energy transfer and energetic charge-carrier generation. Therefore, J-AuPPS shows a higher NIR-activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non-Janus core-particle Au-PPS nanostructure (28.4%). As a result, J-AuPPS exhibits excellent dual-mode (photothermal/photodynamic) antibacterial and anti-biofilm performance, thereby significantly enhancing the in vivo therapeutic effect in an implant-associated-infection rat model. This work is believed to motivate the rational design of advanced hybrid JNPs with desirable NFE effect and further extend their biological applications.
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Affiliation(s)
- Chuanshuang Chen
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Guangyu Chu
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Wanting He
- Énergie Materiaux et Telécommunications, Institut National de la Recherche Scientifique (INRS), 1650 Boulevard Lionel-Boulet, Varennes, QC, J3X 1P7, Canada
| | - Yannan Liu
- Center for Advancing Electronics Dresden (cfaed) and Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01069, Dresden, Germany
| | - Kai Dai
- Department of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai, 200241, China
| | - Jesus Valdez
- Facility for Electron Microscopy Research (FEMR), McGill University, Montréal, QC, H3A 037, Canada
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada
| | - Audrey Moores
- Facility for Electron Microscopy Research (FEMR), McGill University, Montréal, QC, H3A 037, Canada
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada
| | - Pei Huang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Zhaohong Wang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Jiale Jin
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Ming Guan
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Wenfeng Jiang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yiyong Mai
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Dongling Ma
- Énergie Materiaux et Telécommunications, Institut National de la Recherche Scientifique (INRS), 1650 Boulevard Lionel-Boulet, Varennes, QC, J3X 1P7, Canada
| | - Yue Wang
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Yongfeng Zhou
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
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5
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Fiss BG, Douglas G, Ferguson M, Becerra J, Valdez J, Do TO, Friščić T, Moores A. Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide. Beilstein J Org Chem 2022; 18:1203-1209. [PMID: 36158176 PMCID: PMC9490069 DOI: 10.3762/bjoc.18.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/15/2022] [Indexed: 11/23/2022] Open
Abstract
Herein, we present the bottom-up, mechanochemical synthesis of phosphorus-bridged heptazine-based carbon nitrides (g-h-PCN). The structure of these materials was determined through a combination of powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), 31P magic angle spinning nuclear magnetic resonance (MAS NMR), density functional theory (DFT) and electron energy loss spectroscopy (EELS). Compared to traditional furnace-based techniques, the presented method utilizes milder conditions, as well as shorter reaction times. Both samples of g-h-PCN directly after milling and aging and after an hour of annealing at 300 °C (g-h-PCN300) show a reduction in photoluminescent recombination, as well as a nearly two-time increase in photocurrent under broad spectrum irradiation, which are appealing properties for photocatalysis.
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Affiliation(s)
- Blaine G Fiss
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada
| | - Georgia Douglas
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada
| | - Michael Ferguson
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada
| | - Jorge Becerra
- Department of Chemical Engineering, Laval University, Québec City, Québec, Canada
| | - Jesus Valdez
- Facility for Electron Microscopy Research (FEMR), McGill University, Montréal, Québec, Canada
| | - Trong-On Do
- Department of Chemical Engineering, Laval University, Québec City, Québec, Canada
| | - Tomislav Friščić
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada
| | - Audrey Moores
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada
- Department of Materials Engineering, McGill University, 3610 University Street, Montréal, Québec, Canada
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Liu Y, Chen C, Valdez J, Motta Meira D, He W, Wang Y, Harnagea C, Lu Q, Guner T, Wang H, Liu CH, Zhang Q, Huang S, Yurtsever A, Chaker M, Ma D. Phase-enabled metal-organic framework homojunction for highly selective CO 2 photoreduction. Nat Commun 2021; 12:1231. [PMID: 33623017 PMCID: PMC7902628 DOI: 10.1038/s41467-021-21401-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [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: 07/29/2020] [Accepted: 01/26/2021] [Indexed: 12/15/2022] Open
Abstract
Conversion of clean solar energy to chemical fuels is one of the promising and up-and-coming applications of metal-organic frameworks. However, fast recombination of photogenerated charge carriers in these frameworks remains the most significant limitation for their photocatalytic application. Although the construction of homojunctions is a promising solution, it remains very challenging to synthesize them. Herein, we report a well-defined hierarchical homojunction based on metal-organic frameworks via a facile one-pot synthesis route directed by hollow transition metal nanoparticles. The homojunction is enabled by two concentric stacked nanoplates with slightly different crystal phases. The enhanced charge separation in the homojunction was visualized by in-situ surface photovoltage microscopy. Moreover, the as-prepared nanostacks displayed a visible-light-driven carbon dioxide reduction with very high carbon monooxide selectivity, and excellent stability. Our work provides a powerful platform to synthesize capable metal-organic framework complexes and sheds light on the hierarchical structure-function relationships of metal-organic frameworks.
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Affiliation(s)
- Yannan Liu
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Chuanshuang Chen
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, PR China
| | - Jesus Valdez
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Debora Motta Meira
- CLS@APS sector 20, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA.,Canadian Light Source Inc., Saskatoon, SK, Canada
| | - Wanting He
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Yong Wang
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Catalin Harnagea
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Qiongqiong Lu
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Dresden, Germany
| | - Tugrul Guner
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Hao Wang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, PR China
| | - Cheng-Hao Liu
- Department of Chemistry, McGill University, Montreal, QC, Canada
| | - Qingzhe Zhang
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Shengyun Huang
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Aycan Yurtsever
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Mohamed Chaker
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada
| | - Dongling Ma
- Énergie Matériaux et Télécommunications, Institut National de la Recherche Scientifque (INRS), Varennes, QC, Canada.
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7
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Valdez J, Besteiro LV, Mahfoud Z, Guner T, Yurtsever A. Optical resonances of hollow nanocubes controlled with sub-particle structural morphologies. Nanoscale 2019; 11:13790-13799. [PMID: 31292584 DOI: 10.1039/c9nr02645b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The structural details of nanoparticles at the sub-particle level are critical for our understanding of their functionalities and the basic mechanisms involved in their formation. In particular, the geometries of such features determine the particle's overall optical response. Hollow metallic nanoparticles (hollow-MNPs) that have cubic geometries, with varying morphologies on their walls and voids in their body, offer a platform to study the effects of such structural features on the properties of single nanoparticles and their ensemble. Here, we report the control over sub-particle pinholes and voids by modifying the dynamics of the galvanic reaction, and we connect these structures to the optical response of the hollow nanocubes. We observe that symmetry breakage in individual particles, caused by pinholes and voids, has a drastic effect on the plasmon-resonance peak positions in their UV-Vis-NIR spectra. Via electron microscopy imaging, statistical analyses, and electromagnetic simulations, we observe that enlargement in a pinhole's diameter and an increase in their number produce a redshift in the resonance absorption peak of the ensemble. Our results outline nanoparticle design avenues via sub-particle morphologies for several applications, including those operating in the biological window and those carrying chemical payloads in organisms.
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Affiliation(s)
- Jesus Valdez
- Centre Energie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Montreal, QC J3X 1S2, Canada.
| | - Lucas V Besteiro
- Centre Energie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Montreal, QC J3X 1S2, Canada. and Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Zackaria Mahfoud
- Centre Energie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Montreal, QC J3X 1S2, Canada.
| | - Tugrul Guner
- Centre Energie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Montreal, QC J3X 1S2, Canada.
| | - Aycan Yurtsever
- Centre Energie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), Montreal, QC J3X 1S2, Canada.
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8
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Valdez J, Bawage S, Gomez I, Singh SR. Facile and rapid detection of respiratory syncytial virus using metallic nanoparticles. J Nanobiotechnology 2016; 14:13. [PMID: 26921130 PMCID: PMC4769566 DOI: 10.1186/s12951-016-0167-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 11/03/2015] [Accepted: 02/17/2016] [Indexed: 01/20/2023] Open
Abstract
Background Respiratory syncytial virus (RSV) causes severe respiratory infection in infants, children and elderly. Currently, there is no effective vaccine or RSV specific drug for the treatment. However, an antiviral drug ribavirin and palivizumab is prescribed along with symptomatic treatment. RSV detection is important to ensure appropriate treatment of children. Most commonly used detection methods for RSV are DFA, ELISA and Real-time PCR which are expensive and time consuming. Newer approach of plasmonic detection techniques like localized surface plasmon resonance (LSPR) spectroscopy using metallic nanomaterials has gained interest recently. The LSPR spectroscopy is simple and easy than the current biophysical detection techniques like surface-enhanced Raman scattering (SERS) and mass-spectroscopy. Results In this study, we utilized LSPR shifting as an RSV detection method by using an anti-RSV polyclonal antibody conjugated to metallic nanoparticles (Cu, Ag and Au). Nanoparticles were synthesized using alginate as a reducing and stabilizing agent. RSV dose and time dependent LSPR shifting was measured for all three metallic nanoparticles (non-functionalized and functionalized). Specificity of the functionalized nanoparticles for RSV was evaluated in the presence Pseudomonas aeruginosa and adenovirus. We found that functionalized copper nanoparticles were efficient in RSV detection. Functionalized copper and silver nanoparticles were specific for RSV, when tested in the presence of adenovirus and P. aeruginosa, respectively. Limit of detection and limit of quantification values reveal that functionalized copper nanoparticles are superior in comparison with silver and gold nanoparticles. Conclusions The study demonstrates successful application of LSPR for RSV detection, and it provides an easy and inexpensive alternative method for the potential development of LSPR-based detection devices. Electronic supplementary material The online version of this article (doi:10.1186/s12951-016-0167-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jesus Valdez
- Laboratorio de Materiales I, Facultad de Ciencias Químicas, Centro de Laboratorios Especializados, Universidad Autónoma de Nuevo León, Av. Pedro de Alba, 66451, Monterrey, Nuevo León, Mexico.
| | - Swapnil Bawage
- Center for NanoBiotechnology Research, Alabama State University, 1627, Harris way, Montgomery, AL, 36104, USA.
| | - Idalia Gomez
- Laboratorio de Materiales I, Facultad de Ciencias Químicas, Centro de Laboratorios Especializados, Universidad Autónoma de Nuevo León, Av. Pedro de Alba, 66451, Monterrey, Nuevo León, Mexico.
| | - Shree Ram Singh
- Center for NanoBiotechnology Research, Alabama State University, 1627, Harris way, Montgomery, AL, 36104, USA.
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9
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Gonzalez G, Valdez M, Gutierrez R, Valdez J, McLaughlin T, Cherukury H, Chen H, Leon‐Olea M, Curras‐Collazo M. Perinatal Exposure to Brominated Flame Retardants Reduces Social Recognition Ability in Adult Male Mice. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.840.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- G Gonzalez
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - M Valdez
- Neuroscience Graduate Department University of California RiversideRiversideCAUnited States
| | - R Gutierrez
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - J Valdez
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - T McLaughlin
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - H Cherukury
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - H Chen
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
| | - M Leon‐Olea
- Depto. de Neurmofologia Funcional Instituto Nacional de PsiquiatriaMexico CityMexico
| | - M Curras‐Collazo
- Neuroscience Graduate Department University of California RiversideRiversideCAUnited States
- Department of Cell Biology and Neuroscience University of California RiversideRiversideCAUnited States
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Townsley D, Desmond R, Weinstein B, Parikh A, Valdez J, Dumitriu B, Winkler T, Olnes M, Dunbar C, Young N. 56 ELTROMBOPAG FOR LOW TO INTERMEDIATE-2 RISK MYELODYSPLASTIC SYNDROME. Leuk Res 2015. [DOI: 10.1016/s0145-2126(15)30057-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Herman SEM, Niemann CU, Farooqui M, Jones J, Mustafa RZ, Lipsky A, Saba N, Martyr S, Soto S, Valdez J, Gyamfi JA, Maric I, Calvo KR, Pedersen LB, Geisler CH, Liu D, Marti GE, Aue G, Wiestner A. Ibrutinib-induced lymphocytosis in patients with chronic lymphocytic leukemia: correlative analyses from a phase II study. Leukemia 2014; 28:2188-96. [PMID: 24699307 PMCID: PMC4185271 DOI: 10.1038/leu.2014.122] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [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: 01/06/2014] [Revised: 02/21/2014] [Accepted: 03/21/2014] [Indexed: 02/06/2023]
Abstract
Ibrutinib and other targeted inhibitors of B-cell receptor signaling achieve impressive clinical results for patients with chronic lymphocytic leukemia (CLL). A treatment-induced rise in absolute lymphocyte count (ALC) has emerged as a class effect of kinase inhibitors in CLL and warrants further investigation. We here report correlative studies in 64 patients with CLL treated with ibrutinib. We quantified tumor burden in blood, lymph nodes, spleen, and bone marrow, assessed phenotypic changes of circulating cells, and measured whole blood viscosity. With just one dose of ibrutinib the average increase in ALC was 66%, and in over 40% of patients the ALC peaked within 24 hours of initiating treatment. Circulating CLL cells on day 2 showed increased Ki67 and CD38 expression, indicating an efflux of tumor cells from the tissue compartments into the blood. The kinetics and degree of the treatment-induced lymphocytosis was highly variable; interestingly in patients with a high baseline ALC the relative increase was mild and resolution rapid. After two cycles of treatment the disease burden in lymph node, bone marrow, and spleen decreased irrespective of the relative change in ALC. Whole blood viscosity was dependent on both ALC and hemoglobin. No adverse events were attributed to the lymphocytosis.
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Affiliation(s)
- S E M Herman
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - C U Niemann
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - M Farooqui
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - J Jones
- 1] Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA [2] Medical Research Scholars Program, National Institutes of Health, Bethesda, MD, USA
| | - R Z Mustafa
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - A Lipsky
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - N Saba
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - S Martyr
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - S Soto
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - J Valdez
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - J A Gyamfi
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - I Maric
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - K R Calvo
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - L B Pedersen
- Department of Hematology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - C H Geisler
- Department of Hematology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - D Liu
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - G E Marti
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - G Aue
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - A Wiestner
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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Valle RF, Valdez J, Wright TC, Kenney M. Concomitant Essure®⁎ ⁎Essure® Permanent Birth Control System, Conceptus Inc., San Carlos, California. tubal sterilization and Thermachoice®† †Balloon Uterine Therapy System IIIC, Gynecare Thermachoice®, Ethicon, Inc., Somerville, New Jersey. endometrial ablation: feasibility and safety. Fertil Steril 2006; 86:152-8. [PMID: 16762347 DOI: 10.1016/j.fertnstert.2005.12.050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [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: 06/16/2005] [Revised: 12/08/2005] [Accepted: 12/08/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To evaluate the feasibility and safety of combining endometrial ablation (EA) with a thermal balloon endometrial ablation system (Gynecare Thermachoice IIIC Uterine Balloon Therapy System; Ethicon Inc., Somerville, NJ) and transcervical sterilization by intratubal insert (Essure Permanent Birth Control System; Conceptus, San Carlos, CA). DESIGN Feasibility and safety studies. SETTING University hospital in Chihuahua, Mexico. PATIENT(S) There were 40 volunteers in the feasibility study and 9 in the safety study, all requiring hysterectomies for benign uterine bleeding. INTERVENTION(S) In the feasibility study, both procedures were performed just before hysterectomy; in the safety study, thermocouples were inserted under the tubal serosa to assess heat transmission from the intratubal insert devices to the tubes and surrounding organs during EA. MAIN OUTCOME MEASURE(S) Completeness of EA and possible device dislodgement in the feasibility study; temperature readings in the safety study. RESULT(S) No disturbance of the intratubal insert devices was noted, and EA by the thermal balloon endometrial ablation system was complete visually and histologically, although small areas near the tubal ostia exhibited less endometrial destruction. Mean tubal temperatures ranged from 37.1 degrees C to 37.5 degrees C and did not reach the critical temperature of 45 degrees C. No damage to the tubes was noted. CONCLUSION(S) Performance of EA and sterilization with these two systems in a one-step approach is safe for women who require EA and permanent contraception.
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Affiliation(s)
- Rafael F Valle
- Northwestern University Medical School, Chicago, Illinois 60611, USA.
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Aguilera A, Codoceo R, Bajo MA, Diéz JJ, del Peso G, Pavone M, Ortiz J, Valdez J, Cirugeda A, Fernández-Perpén A, Sánchez-Tomero JA, Selgas R. Helicobacter pylori infection: a new cause of anorexia in peritoneal dialysis patients. Perit Dial Int 2002; 21 Suppl 3:S152-6. [PMID: 11887811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
OBJECTIVE Helicobacter pylori (HP) infection has frequently been found in dialysis patients. Chronic infections induce overproduction of pro-inflammatory substances. Inflammation has been associated with cachexia and anorexia. We explored the relationship between HP infection, anorexia, and malnutrition in peritoneal dialysis (PD) patients. PATIENTS AND METHODS The study included 48 clinically stable PD patients divided into four groups: HP+ with anorexia (group I, n = 12); HP+ without anorexia (group II, n = 4); HP- with anorexia (group III, n = 5); and HP- without anorexia (group IV, n = 27). Infection with HP was diagnosed by breath test. Anorexia was evaluated using a personal interview and an eating motivation scale (VAS). The VAS included five questions that are answered before and after eating. The questions concern desire to eat, hunger, feeling of fullness, prospective consumption, and palatability. Biochemical markers of nutrition and inflammation were also determined. RESULTS At baseline, group I showed lower scores for desire to eat, hunger sensation, prospective consumption, and palatability. They also showed lower lymphocyte counts, prealbumin, transferrin, serum albumin, normalized equivalent of protein-nitrogen appearance (nPNA), and residual renal function (RRF). In addition, the same group showed higher levels of C-reactive protein (CRP) and more sensation of fullness than the remaining groups. In the entire series, we found significant linear correlations between the following markers of nutrition and certain questions on the VAS: albumin with before-lunch desire to eat (r = 0.38, p < 0.05), and prealbumin with before-lunch hunger (r = 0.41, p < 0.05) and after-lunch hunger (r = -0.35, p < 0.05). Negative linear correlations were found between albumin and fullness before lunch (r = -0.45, p < 0.01), and between prealbumin and before-lunch desire to eat (r = -0.39, p < 0.05). Negative linear correlations were also seen between CRP and albumin (r = -0.35, p < 0.05) and between CRP and prealbumin (r = -0.36, p < 0.05). Similarly, CRP showed a negative correlation with before-lunch desire to eat (r = -0.38, p < 0.05) and afterlunch desire to eat (r = -0.45, p < 0.01). After HP eradication, group I showed a significant increase in markers of nutrition and in VAS scores for almost all questions. Simultaneously, they showed a decrease in CRP level. Significant differences were also found in lymphocyte count (1105 +/- 259.4 cells/mm3 vs 1330.8 +/- 316 cells/mm3, p < 0.05), nPNA (0.9 +/- 0.16 g/kg/day vs 1.07 +/- 0.3 g/kg/day, p < 0.05), prealbumin (26.7 +/- 6.5 mg/dL vs 33.9 +/- 56.6 mg/dL, p < 0.01), albumin (3.48 +/- 0.3 g/dL vs 3.67 +/- 0.35 g/dL, p < 0.05), CRP (1.16 +/- 1.14 mg/dL vs 0.88 +/- 1.2 mg/dL, p < 0.054), before-lunch desire to eat (56.6 +/- 6.8 vs 72.2 +/- 4, p < 0.001), after-lunch desire to eat (5.4 +/- 2.6 vs 12.3 +/- 2, p < 0.01), hunger before lunch (55.4 +/- 5.4 vs 73.1 +/- 4.6, p < 0.001), hunger after lunch (5.8 +/- 2.9 vs 11 +/- 4, p < 0.01), fullness before lunch (36.6 +/- 10.3 vs 18.7 +/- 8.8, p < 0.001), consumption after lunch (5 +/- 4.7 vs 17.5 +/- 18, p < 0.05), and palatability (61 +/- 5.3 vs 74.1 +/- 4.1, p < 0.001). CONCLUSION Infection with HP is associated with anorexia, inflammation, and malnutrition in PD patients. Eradication of HP significantly improves this syndrome. Residual renal function seem to have a protective effect on appetite preservation. The present study supports the hypothesis of the involvement of inflammation in the pathogenesis of malnutrition in PD patients.
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Affiliation(s)
- A Aguilera
- Laboratorio de Gastroenterología, Hospitales Universitarios de la Princesa y la Paz, Madrid, Spain
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14
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Abstract
The beneficial effect of yoghurt consumption on health and on the improvement of the mucosal immune system is well established, as is the diet-associated risk of colon cancer. In an experimental model in BALB/c mice we demonstrated that yoghurt added to the diet for 10 consecutive days, with the procedure repeated each 10 days for 6 months, inhibited the development of a colorectal carcinoma induced by 1,2 dimethylhydrazine (DMH). The immunoregulatory mechanisms involved in the inhibition of tumour growth by yoghurt were also examined in these studies. We determined B lymphocytes IgA(+) and IgG(+), as well as CD4(+) and CD8(+) T cells in the large intestine. We measured cellular apoptosis and the cytokines TNF-alpha, IFN-gamma and IL-10. An increase in the number of IgA(+) (P<0.01) was observed, but not in IgG(+) (P<0.01), or in the CD4(+) population (P<0.01) in the mice treated with DMH and yoghurt. While in the group with the carcinogen there was an enhancement in the IgG(+) B cells (P<0.01) and CD8(+) T cells (P<0.01). Yoghurt increased the number of apoptotic cells and induced IFN-gamma and TNF-alpha cytokine release, their production being regulated by an increase in IL-10 (P<0.001). We demonstrated that yoghurt may exert antitumour activity by a decrease in the inflammatory immune response mediated by IgA(+) increase, apoptosis induction and IL-10 release.
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Affiliation(s)
- G Perdigón
- Cátedra de Inmunología, Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Tucumán, Argentina.
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15
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Derjuga A, Richard C, Crosato M, Wright PS, Chalifour L, Valdez J, Barraso A, Crissman HA, Nishioka W, Bradbury EM, Th'ng JP. Expression of p21Waf1/Cip1 and cyclin D1 is increased in butyrate-resistant HeLa cells. J Biol Chem 2001; 276:37815-20. [PMID: 11477082 DOI: 10.1074/jbc.m104735200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sodium butyrate induced cell cycle arrest in mammalian cells through an increase in p21Waf1/Cip1, although another study showed that this arrest is related to pRB signaling. We isolated variants of HeLa cells adapted to growth in 5 mm butyrate. One of these variants, clone 5.1, constitutively expressed elevated levels of p21Waf1/Cip1 when incubated in regular growth medium and in the presence of butyrate. Despite this elevated level of p21Waf1/Cip1, the cells continue to proliferate, albeit at a slower rate than parental HeLa cells. Western blot analyses showed that other cell cycle regulatory proteins were not up-regulated to compensate for the elevated expression of p21Waf1/Cip1. However, cyclin D1 was down-regulated by butyrate in HeLa cells but not in clone 5.1. We conclude that continued expression of cyclin D1 allowed clone 5.1 to grow in the presence of butyrate and elevated levels of p21Waf1/Cip1.
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Affiliation(s)
- A Derjuga
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, H3T 1E2, Canada
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16
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Navarrete-Vázquez G, Cedillo R, Hernández-Campos A, Yépez L, Hernädez-Luis F, Valdez J, Morales R, Cortés R, Hernández M, Castillo R. Synthesis and antiparasitic activity of 2-(trifluoromethyl)-benzimidazole derivatives. Bioorg Med Chem Lett 2001; 11:187-90. [PMID: 11206455 DOI: 10.1016/s0960-894x(00)00619-3] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
2-(Trifluoromethyl)benzimidazole derivatives substituted at the 1-, 5-, and 6-positions have been synthesized and in vitro tested against the protozoa Giardia lamblia, Entamnoeha histolytica. and the helminth Trichinella spiralis. Results indicate that all the compounds tested are more active as antiprotozoal agents than Albendazole and Metronidazole. One compound (20) was as active as Albendazole against T. spiralis. These compounds were also tested for their effect on tubulin polymerization and none inhibited tubulin polymerization.
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17
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Biehl JW, Valdez J, Hemady RK, Steidl SM, Bourke DL. Penetrating eye injury in war. Mil Med 1999; 164:780-4. [PMID: 10578588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The percentage of penetrating eye injuries in war has increased significantly in this century compared with the total number of combat injuries. With the increasing use of fragmentation weapons and possibly laser weapons on the battle-field in the future, the rate of eye injuries may exceed the 13% of the total military injuries found in Operations Desert Storm/Shield. During the Iran-Iraq War (1980-1988), eye injuries revealed that retained foreign bodies and posterior segment injuries have an improved prognosis in future military ophthalmic surgery as a result of modern diagnostic and treatment modalities. Compared with the increasing penetrating eye injuries on the battlefield, advances in ophthalmic surgery are insignificant. Eye armor, such as visors that flip up and down and protect the eyes from laser injury, needs to be developed. Similar eye protection is being developed in civilian sportswear. Penetrating eye injury in the civilian sector is becoming much closer to the military model and is now comparable for several reasons.
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Affiliation(s)
- J W Biehl
- Anesthesia Service, Veterans Administration Medical Center, Baltimore, MD, USA
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18
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Garcia HH, Araoz R, Gilman RH, Valdez J, Gonzalez AE, Gavidia C, Bravo ML, Tsang VC. Increased prevalence of cysticercosis and taeniasis among professional fried pork vendors and the general population of a village in the Peruvian highlands. Cysticercosis Working Group in Peru. Am J Trop Med Hyg 1998; 59:902-5. [PMID: 9886197 DOI: 10.4269/ajtmh.1998.59.902] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Two different populations in Saylla, a Peruvian village near Cusco, known for chicharrones, a local pork dish, were surveyed by serology and stool examination to determine the prevalence and epidemiologic characteristics of Taenia solium infection. Group I (n=43), the chicharroneros, were members of families professionally devoted to the making and selling of chicharrones, and Group II (n=102) was a sample of the general population of the same village. Unlike people in Group I, general villagers only occasionally prepare or sell this food product, and then only to their neighbors or relatives. The prevalence of taeniasis was extremely high (8.6%) for the chicharroneros and 3% for the general villagers. Seroprevalence for cysticercosis by immunoblot was similarly high in both groups (23.3% and 23.8%, respectively). Being female, older than 30, and having daily contact with pork were factors strongly associated with a positive serologic result for cysticercosis in the chicharroneros, whereas males were more frequently seropositive in the general villagers group. Antibody reaction to more antigen bands in immunoblots and neurologic symptoms were more common among the chicharroneros. Also, in the general villagers group, seroprevalence increased with each exposure factor, ranging from 9.4% in individuals who did not raise pigs to 50% in the small subgroup that raised pigs, butchered their own animals, sold pork, and sold chicharrones, suggesting that these activities are related to increased risk for tapeworm or larval infection.
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Affiliation(s)
- H H Garcia
- Department of Microbiology, Universidad Peruana Cayetano Heredia, San Martin de Porras, Lima, Peru
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Diallinas G, Valdez J, Sophianopoulou V, Rosa A, Scazzocchio C. Chimeric purine transporters of Aspergillus nidulans define a domain critical for function and specificity conserved in bacterial, plant and metazoan homologues. EMBO J 1998; 17:3827-37. [PMID: 9670000 PMCID: PMC1170718 DOI: 10.1093/emboj/17.14.3827] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In Aspergillus nidulans, purine uptake is mediated by three transporter proteins: UapA, UapC and AzgA. UapA and UapC have partially overlapping functions, are 62% identical and have nearly identical predicted topologies. Their structural similarity is associated with overlapping substrate specificities; UapA is a high-affinity, high-capacity specific xanthine/uric acid transporter. UapC is a low/moderate-capacity general purine transporter. We constructed and characterized UapA/UapC, UapC/UapA and UapA/UapC/UapA chimeric proteins and UapA point mutations. The region including residues 378-446 in UapA (336-404 in UapC) has been shown to be critical for purine recognition and transport. Within this region, we identified: (i) one amino acid residue (A404) important for transporter function but probably not for specificity and two residues (E412 and R414) important for UapA function and specificity; and (ii) a sequence, (F/Y/S)X(Q/E/P) NXGXXXXT(K/R/G), which is highly conserved in all homologues of nucleobase transporters from bacteria to man. The UapC/UapA series of chimeras behaves in a linear pattern and leads to an univocal assignment of functional domains while the analysis of the reciprocal and 'sandwich' chimeras revealed unexpected inter-domain interactions. cDNAs coding for transporters including the specificity region defined by these studies have been identified for the first time in the human and Caenorhabditis elegans databases.
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Affiliation(s)
- G Diallinas
- Institute of Molecular Biology and Biotechnology, FORTH, P.O. Box 1527, Heraklion 71110, Crete
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20
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Montemayor Garza R, Cruz Salas CA, Montoya Garza D, Valdez J, Galache Vega P, Santos Halaiscak R, Hernández Ayup S, Ruy M, García Villafaña G, Martínez Caudillo G. [Ovum donation: a 3-year experience at the Gynecologic and Obstetric Center of Monterrey, Mexico]. Ginecol Obstet Mex 1998; 66:214-20. [PMID: 9646579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Evaluating the rate of pregnancies, neonates, implantation rate and kinds of donor in our program Assisted Reproduction with oocyte donation. INTRODUCTION The oocyte donation is the most important support in assisted reproduction because in patients with ovarian failure, offering the same opportunity to female without ovarian alterations to increase the rate of pregnancies. MATERIAL AND METHOD 98 donor's procedures were included in host patients; 87 were FIV-TE and 11 GIFT between march to june 1997. The patients were divided in age group: 1) < 30 years, 2) 30 to 34 years, 3) 35 to 39 years, 4) > or = 40 years. The donors were divided in known (26) and unknown (72). The results were analysed. RESULTS 48 pregnancies (55.17%) of the 87 FIV-TE-D group were obtained with 31 neonates The implantation rate was 17.5% to FIV-TE group and 13.8 to GIFT group, 44 (61.11%) pregnancies were from unknown donors group and 9 (34.61%) from known donors group. CONCLUSIONS Our results are similar to others international reports, we have observed a little and significative difference between pregnancy with oocytes from known donors and unknown donors; this is the principal motive to be selective in the suitable known donor.
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21
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Swank RA, Th'ng JP, Guo XW, Valdez J, Bradbury EM, Gurley LR. Four distinct cyclin-dependent kinases phosphorylate histone H1 at all of its growth-related phosphorylation sites. Biochemistry 1997; 36:13761-8. [PMID: 9374852 DOI: 10.1021/bi9714363] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In mammalian cells, up to six serines and threonines in histone H1 are phosphorylated in vivo in a cell cycle dependent manner that has long been linked with chromatin condensation. Growth-associated H1 kinases, now known as cyclin-dependent kinases (CDKs), are thought to be the enzymes responsible for this process. This paper describes the phosphorylation of histone H1 by four different purified CDKs. The four CDKs phosphorylate only the cell cycle specific phosphorylation sites of H1, indicating that they belong to the kinase class responsible for growth-related H1 phosphorylation in vivo. All four CDKs phosphorylate all of the interphase and mitotic-specific H1 sites. In addition to the (S/T)PXK consensus phosphorylation sites, these four CDKs also phosphorylate a mitotic-specific in vivo H1 phosphorylation site that lacks this sequence. There is no site selectivity among the growth-related phosphorylation sites by any of the four CDKs because all four CDKs phosphorylate all relevant sites. The results imply that the cell cycle dependent H1 phosphorylations observed in vivo must involve differential accessibility of H1 sites at different stages of the cell cycle.
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Affiliation(s)
- R A Swank
- School of Medicine, Department of Biological Chemistry, University of California-Davis 95616, USA
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Abstract
Complementation group G of xeroderma pigmentosum (XPG) is one of the most rare and pathophysiologically heterogeneous forms of this inherited disease. XPG patients exhibit varying phenotypes, from having a very mild defect in DNA repair to being severely affected, and a few cases are also associated with the neurological degeneracy and growth retardation of Cockayne's syndrome. The XPG gene encodes a 134-kDa nuclear protein that is essential for the incision steps of nucleotide excision repair. XPG protein contains a putative helix-loop-helix (HLH) motif in the region that is most conserved among the members of structure-specific endonuclease family. To establish the functional significance of the HLH motif, we used several approaches, including theoretical modeling, functional complementation assay, structure-specific endonuclease assay, and DNA binding assay. A secondary structure of the motif was predicted by energy minimization and the Monte Carlo simulation and empirically proven using the circular dichroism to contain a high content of alpha-helix. When an XPG mutant lacking the HLH was overexpressed in UV135 cells, which have defects in the hamster homolog of XPG, the mutant gene failed to confer to the hamster cells the resistance to UV light. A recombinant XPG protein lacking the HLH motif was purified from insect cells and tested for a structure-specific endonuclease activity. The mutant protein failed to cleave the flap strand. A recombinant peptide containing the HLH (amino acids 758-871) was expressed in and purified from bacteria, tested for DNA binding activity, and found to bind to a DNA substrate with the flap structure. These results suggest that the HLH motif is required for the catalytic and DNA binding activities of XPG.
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Affiliation(s)
- M S Park
- Life Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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23
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Salas L, Gutiérrez L, Pedrayes MH, Valdez J, Carrasco C, Carrillo M, Orozco B, García B, Luna E, Ruiz E, Cuevas S, Iriarte A, Cordero A, Harris O, Quiroz F, Sohn E, Martínez LA. Active primary mirror support for the 2.1-m telescope at the San Pedro Mártir Observatory. Appl Opt 1997; 36:3708-3716. [PMID: 18253396 DOI: 10.1364/ao.36.003708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have designed and installed a new set of actuators for the suspension of the primary mirror of the 2.1-m telescope at San Pedro Mártir. This active optics system has allowed us to correct low-order aberrations identified by several wave-front analysis techniques.
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Valdez J, Césarman E, Soberón J. [Myocardial infarct. Anatomoclinical study]. Arch Inst Cardiol Mex 1965; 35:324-49. [PMID: 5846715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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