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Bodart-Santos V, Pinheiro LS, da Silva-Junior AJ, Froza RL, Ahrens R, Gonçalves RA, Andrade MM, Chen Y, Alcantara CDL, Grinberg LT, Leite REP, Ferreira ST, Fraser PE, De Felice FG. Alzheimer's disease brain-derived extracellular vesicles reveal altered synapse-related proteome and induce cognitive impairment in mice. Alzheimers Dement 2023; 19:5418-5436. [PMID: 37204850 DOI: 10.1002/alz.13134] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/15/2023] [Accepted: 04/17/2023] [Indexed: 05/20/2023]
Abstract
INTRODUCTION Extracellular vesicles (EVs) have been implicated in the spread of neuropathology in Alzheimer's disease (AD), but their involvement in behavioral outcomes linked to AD remains to be determined. METHODS EVs isolated from post mortem brain tissue from control, AD, or frontotemporal dementia (FTD) donors, as well as from APP/PS1 mice, were injected into the hippocampi of wild-type (WT) or a humanized Tau mouse model (hTau/mTauKO). Memory tests were carried out. Differentially expressed proteins in EVs were assessed by proteomics. RESULTS Both AD-EVs and APP/PS1-EVs trigger memory impairment in WT mice. We further demonstrate that AD-EVs and FTD-EVs carry Tau protein, present altered protein composition associated with synapse regulation and transmission, and trigger memory impairment in hTau/mTauKO mice. DISCUSSION Results demonstrate that AD-EVs and FTD-EVs have negative impacts on memory in mice and suggest that, in addition to spreading pathology, EVs may contribute to memory impairment in AD and FTD. HIGHLIGHTS Aβ was detected in EVs from post mortem AD brain tissue and APP/PS1 mice. Tau was enriched in EVs from post mortem AD, PSP and FTD brain tissue. AD-derived EVs and APP/PS1-EVs induce cognitive impairment in wild-type (WT) mice. AD- and FTD-derived EVs induce cognitive impairment in humanized Tau mice. Proteomics findings associate EVs with synapse dysregulation in tauopathies.
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Affiliation(s)
- Victor Bodart-Santos
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Lisandra S Pinheiro
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Almir J da Silva-Junior
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rudimar L Froza
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, FIOCRUZ, Rio de Janeiro, Brazil
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Rafaella A Gonçalves
- Centre for Neuroscience Studies, Department of Biomedical and Molecular Sciences and Department of Psychiatry, Queen's University, Kingston, Canada
| | - Mayara M Andrade
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Yan Chen
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Carolina de Lima Alcantara
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lea T Grinberg
- Department of Pathology, University of São Paulo Medical School, Sao Paulo, Brazil
- Memory and Aging Center, Department of Neurology and Pathology, University of California San Francisco, San Francisco, California, USA
| | - Renata E P Leite
- Department of Pathology, University of São Paulo Medical School, Sao Paulo, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Centre for Neuroscience Studies, Department of Biomedical and Molecular Sciences and Department of Psychiatry, Queen's University, Kingston, Canada
- D'OR Institute for Research and Education, Rio de Janeiro, Brazil
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Kadagi NI, Wambiji N, Mann B, Parker D, Daly R, Thoya P, Rato DAM, Halafo J, Gaspare L, Sweke EA, Ahmed S, Raseta SB, Osore M, Maina J, Glaser S, Ahrens R, Sumaila UR. Status and challenges for sustainable billfish fisheries in the Western Indian Ocean. Rev Fish Biol Fish 2022; 32:1035-1061. [PMID: 36187439 PMCID: PMC9510346 DOI: 10.1007/s11160-022-09725-8] [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] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 07/12/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED Billfish species (families Istiophoridae and Xiphiidae) are caught in artisanal, recreational, and commercial fisheries throughout the Western Indian Ocean region. However, data and information on the interactions among these fisheries and the ecology of billfish in the WIO are not well understood. Using an in-depth analysis of peer-reviewed articles, grey literature, observation studies, and authors' insider knowledge, we summarize the current state of knowledge on billfish fisheries in 10 countries. To describe historical and current trends, we examined fisheries statistics from governmental and non-governmental agencies, sportfishing clubs' reports, diaries of sportfishing captains, and the catch and effort databases of the Indian Ocean Tuna Commission. We highlight two key points. First, billfish fisheries in the Western Indian Ocean are highly diverse, comprising two distinct segments-coastal and oceanic. However, data are poor for most countries with significant gaps in information especially for sport and artisanal fisheries. Second, the evidence assembled showed that billfish species have immense social, cultural, and economic value. Swordfish are targeted by both large-scale and semi-industrial fisheries, while other billfish species, particularly marlin, are highly sought after by sport fisheries in most countries. Our paper provides a comprehensive review of billfish fisheries and available information in the context of the WIO underscoring the need to strengthen data collection and reporting, citizen science, and collaborative sustainable development and management of billfish. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s11160-022-09725-8.
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Affiliation(s)
| | - N. Wambiji
- Kenya Marine and Fisheries Research Institute, Mombasa, Kenya
| | - B. Mann
- Oceanographic Research Institute and South African Association for Marine Biological Research, Durban, South Africa
| | - D. Parker
- Department of Agriculture, Forestry and Fisheries, Pretoria, South Africa
| | - R. Daly
- Oceanographic Research Institute and South African Association for Marine Biological Research, Durban, South Africa
| | - P. Thoya
- Kenya Marine and Fisheries Research Institute, Mombasa, Kenya
- Department of Earth and Environmental Sciences, Macquarie University, Sydney, Australia
- Institute for Marine Ecosystem and Fisheries Science, Center for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
- Leibniz Institute for Baltic Sea Research Warnemuende (IOW), Rostock, Germany
| | | | - J. Halafo
- Mozambique Oceanographic Institute (InOM), Maputo, Mozambique
| | - L. Gaspare
- University of Dar es Salaam, Dar es Salaam, Tanzania
| | - E. A. Sweke
- Deep Sea Fisheries Authority, Zanzibar, Tanzania
| | - S. Ahmed
- University of Dodoma, Dodoma, Tanzania
| | | | - M. Osore
- Kenya Marine and Fisheries Research Institute, Mombasa, Kenya
| | - J. Maina
- Department of Earth and Environmental Sciences, Macquarie University, Sydney, Australia
| | - S. Glaser
- World Wildlife Fund, Washington, DC, USA
| | - R. Ahrens
- Pacific Islands Fisheries Science Center, National Marine Fisheries Service, 1845 Wasp Blvd., Building 176, Honolulu, HI 96818 USA
| | - U. R. Sumaila
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada
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Finkbeiner T, Manz C, Raorane ML, Metzger C, Schmidt-Speicher L, Shen N, Ahrens R, Maisch J, Nick P, Guber AE. A modular microfluidic bioreactor to investigate plant cell-cell interactions. Protoplasma 2022; 259:173-186. [PMID: 33934215 PMCID: PMC8752559 DOI: 10.1007/s00709-021-01650-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 06/30/2020] [Accepted: 04/20/2021] [Indexed: 05/04/2023]
Abstract
Plants produce a wide variety of secondary metabolites, which often are of interest to pharmaceutical and nutraceutical industry. Plant-cell cultures allow producing these metabolites in a standardised manner, independently from various biotic and abiotic factors difficult to control during conventional cultivation. However, plant-cell fermentation proves to be very difficult, since these chemically complex compounds often result from the interaction of different biosynthetic pathways operating in different cell types. To simulate such interactions in cultured cells is a challenge. Here, we present a microfluidic bioreactor for plant-cell cultivation to mimic the cell-cell interactions occurring in real plant tissues. In a modular set-up of several microfluidic bioreactors, different cell types can connect through a flow that transports signals or metabolites from module to module. The fabrication of the chip includes hot embossing of a polycarbonate housing and subsequent integration of a porous membrane and in-plane tube fittings in a two-step ultrasonic welding process. The resulting microfluidic chip is biocompatible and transparent. Simulation of mass transfer for the nutrient sucrose predicts a sufficient nutrient supply through the membrane. We demonstrate the potential of this chip for plant cell biology in three proof-of-concept applications. First, we use the chip to show that tobacco BY-2 cells in suspension divide depending on a "quorum-sensing factor" secreted by proliferating cells. Second, we show that a combination of two Catharanthus roseus cell strains with complementary metabolic potency allows obtaining vindoline, a precursor of the anti-tumour compound vincristine. Third, we extend the approach to operationalise secretion of phytotoxins by the fungus Neofusicoccum parvum as a step towards systems to screen for interorganismal chemical signalling.
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Affiliation(s)
- T Finkbeiner
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - C Manz
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - M L Raorane
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
- Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Biosynthesis of active substances, Hoher Weg 8, 06120, Halle (Saale), Germany
| | - C Metzger
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - L Schmidt-Speicher
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - N Shen
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - R Ahrens
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
| | - J Maisch
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - P Nick
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - A E Guber
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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Wijesekara N, Ahrens R, Wu L, Langman T, Tandon A, Fraser PE. α-Synuclein Regulates Peripheral Insulin Secretion and Glucose Transport. Front Aging Neurosci 2021; 13:665348. [PMID: 34393754 PMCID: PMC8361797 DOI: 10.3389/fnagi.2021.665348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 02/07/2021] [Accepted: 07/05/2021] [Indexed: 11/23/2022] Open
Abstract
Aim Population based studies indicate a positive association between type 2 diabetes (T2D) and Parkinson’s disease (PD) where there is an increased risk of developing PD in patients with T2D. PD is characterized by the abnormal accumulation of intraneuronal aggregated α-synuclein (α-syn) in Lewy bodies, which negatively impact neuronal viability. α-syn is also expressed in both pancreatic islets and skeletal muscle, key players in glucose regulation. Therefore, we examined the functional role of α-syn in these tissues. Methods Using mice lacking, overexpressing or transiently injected with α-syn, effects on glucose and insulin tolerance and insulin secretion were determined, with further characterization of the effects on GLUT4 translocation using GLUT4myc myotubes. Results Mice genetically ablated for α-syn became glucose intolerant and insulin resistant with hyperinsulinemia and reduced glucose-stimulated insulin secretion (GSIS). Mice overexpressing human α-syn are more insulin senstive and glucose tolerant compared to controls with increased GSIS. Injection of purified α-syn monomers also led to improved glucose tolerance and insulin sensitivity with hightened GSIS. α-syn monomer treatments increased surface GLUT4 levels in myotubes but without any significant change in Akt phosphorylation. The increase in cell surface GLUT4 was largely due to a large reduction in GLUT4 endocytosis, however, with a compensatory reduction in GLUT4 exocytosis. Conclusion Cumulatively, this data suggests that α-syn modulates both pancreatic beta cell function and glucose transport in peripheral tissues, thereby playing a pivitol role in the maintenance of normal glucose homeostasis.
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Affiliation(s)
- Nadeeja Wijesekara
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Ling Wu
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Tammy Langman
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Anurag Tandon
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
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Wijesekara N, Gonçalves RA, Ahrens R, Ha K, De Felice FG, Fraser PE. Combination of human tau and islet amyloid polypeptide exacerbates metabolic dysfunction in transgenic mice. J Pathol 2021; 254:244-253. [PMID: 33797777 DOI: 10.1002/path.5674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/07/2021] [Accepted: 03/29/2021] [Indexed: 11/07/2022]
Abstract
Amyloid plaques and neurofibrillary tangles composed of hyperphosphorylated tau are important contributors to Alzheimer's disease (AD). Tau also impacts pancreatic beta cell function and glucose homeostasis. Amyloid deposits composed of islet amyloid polypeptide (IAPP) are a pathological feature of type 2 diabetes (T2D). The current study investigates the role of human tau (hTau) in combination with human IAPP (hIAPP) as a potential mechanism connecting AD and T2D. Transgenic mice expressing hTau and hIAPP in the absence of murine tau were generated to determine the impact of these pathological factors on glucose metabolism. Co-expression of hIAPP and hTau resulted in mice with increased hyperglycaemia, insulin resistance, and glucose intolerance. The hTau-hIAPP mice also exhibited reduced beta cell area, increased amyloid deposition, impaired insulin processing, and reduced insulin content in islets. Tau phosphorylation also increased after stimulation with high glucose. In addition, brain insulin content and signalling were reduced, and tau phosphorylation was increased in these animals. These data support a link between tau and IAPP amyloid, which seems to act co-ordinately to impair beta cell function and glucose homeostasis, and suggest that the combined pathological actions of these proteins may be a potential mechanism connecting AD and T2D. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Nadeeja Wijesekara
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Rafaella Araujo Gonçalves
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
- Centre for Neuroscience Studies and Department of Psychiatry, Queen's University, Kingston, Canada
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Kathy Ha
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Fernanda G De Felice
- Centre for Neuroscience Studies and Department of Psychiatry, Queen's University, Kingston, Canada
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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Doll PW, Wolf M, Guttmann M, Thelen R, Ahrens R, Spindler B, Guber AE, Al-Ahmad A. Initial Bacterial Adhesion Properties of Anodically Oxidized Ti 6Al 4V. Annu Int Conf IEEE Eng Med Biol Soc 2019; 2019:6476-6480. [PMID: 31947325 DOI: 10.1109/embc.2019.8857956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This paper reports about the initial interaction of bacteria with anodically oxidized Ti6Al4V for the use as dental implant abutment surfaces. Ti6Al4V samples are anodically oxidized in hydrofluoric acid using different voltages. The resulting nanotopographies are characterized by atomic force microscopy, scanning electron microscopy and contact angle measurements. The topographies reach from micro-porous structures with small nanoporosities on top to fully hexagonally aligned nanotubes. For initial bacterial adhesion tests, Escherichia coli and Staphylococcus aureus are used. Samples are incubated for 2 h and afterwards non-adherent cells are washed off. The results of live/dead staining and cell counts are presented. Gram-negative and Gram-positive strains show different behavior in respect to total number of initially adherent cells on different micro/nanotopographies. The observed reduction of adhered microorganisms is mainly based on underlying microporous topographies.
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Wiedmeyer V, Voigt A, Anker F, John V, Ahrens R, Le Borne S, Sundmacher A. Kontinuierliche formselektive Kristallisation: Neue Strategien. CHEM-ING-TECH 2018. [DOI: 10.1002/cite.201855145] [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)
- V. Wiedmeyer
- Otto-von-Guericke-Universität Magdeburg; Systemverfahrenstechnik; Uniplatz 2 39106 Magdeburg Deutschland
| | - A. Voigt
- Otto-von-Guericke-Universität Magdeburg; Systemverfahrenstechnik; Uniplatz 2 39106 Magdeburg Deutschland
| | - F. Anker
- Weierstraß-Institut für Angewandte Analysis und Stochastik; Numerische Mathematik; Mohrenstraße 39 10117 Berlin Deutschland
| | - V. John
- Weierstraß-Institut für Angewandte Analysis und Stochastik; Numerische Mathematik; Mohrenstraße 39 10117 Berlin Deutschland
- Freie Universität Berlin; Mathematik und Computerwissenschaften; Arnimallee 6 14195 Berlin Deutschland
| | - R. Ahrens
- Technische Universität Hamburg; Numerische Mathematik; Am Schwarzenberg-Campus 3 21073 Hamburg Deutschland
| | - S. Le Borne
- Technische Universität Hamburg; Numerische Mathematik; Am Schwarzenberg-Campus 3 21073 Hamburg Deutschland
| | - A. Sundmacher
- Otto-von-Guericke-Universität Magdeburg; Systemverfahrenstechnik; Uniplatz 2 39106 Magdeburg Deutschland
- Max-Planck-Institut für Dynamik komplexer technischer Systeme Magdeburg; Prozesstechnik; Sandtorstraße 1 39106 Magdeburg Deutschland
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Wijesekara N, Gonçalves RA, Ahrens R, De Felice FG, Fraser PE. Tau ablation in mice leads to pancreatic β cell dysfunction and glucose intolerance. FASEB J 2018; 32:3166-3173. [DOI: 10.1096/fj.201701352] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Nadeeja Wijesekara
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of Toronto Toronto Ontario Canada
| | - Rafaella Araujo Gonçalves
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of Toronto Toronto Ontario Canada
- Department of Medical BiophysicsUniversity of Toronto Toronto Ontario Canada
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of Toronto Toronto Ontario Canada
| | - Fernanda G. De Felice
- Department of Medical BiophysicsUniversity of Toronto Toronto Ontario Canada
- Institute of Medical Biochemistry Leopoldo de MeisFederal University of Rio de Janeiro Rio de Janeiro Brazil
| | - Paul E. Fraser
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of Toronto Toronto Ontario Canada
- Department of Biomedical and Molecular SciencesCentre for Neuroscience StudiesQueen's University Kingston Ontario Canada
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Kent BA, Heath CJ, Kim CH, Ahrens R, Fraser PE, St George‐Hyslop P, Bussey TJ, Saksida LM. Longitudinal evaluation of Tau-P301L transgenic mice reveals no cognitive impairments at 17 months of age. Brain Behav 2018; 8:e00896. [PMID: 29568692 PMCID: PMC5853624 DOI: 10.1002/brb3.896] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/07/2017] [Accepted: 11/15/2017] [Indexed: 01/01/2023] Open
Abstract
Introduction Tau is a microtubule-associated binding protein implicated in neurodegenerative tauopathies, including frontotemporal dementia (FTD) and Alzheimer's disease (AD). These diseases result in the intracellular accumulation of hyperphosphorylated tau in the form of neurofibrillary tangles, the presence of which is associated with cognitive deficits. Methods We conducted a longitudinal behavioral study to provide a profile of the TgTau(P301L)23027 transgenic mouse in multiple cognitive domains across multiple ages. P301L is the tau mutation most frequently observed in patients with frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) and this mouse model recapitulates the progressive development of glial and neurofibrillary tangles, and associated cerebral atrophy observed in patients. We examined frontal cortex-dependent executive function and attention with the touchscreen 5-choice serial reaction time test (5-CSRTT) and assessed the function of temporal cortical structures using novel object recognition (OR). Results Despite using sensitive tasks, there were no apparent changes in executive function, attention, or recognition memory in the transgenic mice from 5 to 17 months of age. Conclusions This study represents the first comprehensive longitudinal analysis of cognition in the TgTauP301L mouse model and suggests that this model is not ideal for studying early attention and recognition memory impairments associated with tauopathy. However, spatial and object recognition memory impairments were observed during follow-up assessments when the mice were 18 and 21 months, respectively. These impairments are consistent with previous publications, and with a dementia-like phenotype in these mice when aged.
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Affiliation(s)
- Brianne A. Kent
- Department of MedicineUniversity of British ColumbiaVancouverBCCanada
| | - Christopher J. Heath
- Department of Life, Health and Chemical SciencesThe Open UniversityMilton KeynesUK
| | - Chi Hun Kim
- Department of PsychiatryUniversity of OxfordOxfordUK
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada
| | - Paul E. Fraser
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada
| | - Peter St George‐Hyslop
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Timothy J. Bussey
- Department of Psychology and MRC & Wellcome Trust Behavioural and Clinical Neuroscience InstituteUniversity of CambridgeCambridgeUK
- Molecular Medicine Research Group, Robarts Research Institute & Department of Physiology and Pharmacology, Schulich School of Medicine & DentistryWestern UniversityLondonONCanada
- The Brain and Mind InstituteWestern UniversityLondonONCanada
| | - Lisa M. Saksida
- Department of Psychology and MRC & Wellcome Trust Behavioural and Clinical Neuroscience InstituteUniversity of CambridgeCambridgeUK
- Molecular Medicine Research Group, Robarts Research Institute & Department of Physiology and Pharmacology, Schulich School of Medicine & DentistryWestern UniversityLondonONCanada
- The Brain and Mind InstituteWestern UniversityLondonONCanada
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Wijesekara N, Ahrens R, Sabale M, Wu L, Ha K, Verdile G, Fraser PE. Amyloid-β and islet amyloid pathologies link Alzheimer's disease and type 2 diabetes in a transgenic model. FASEB J 2017; 31:5409-5418. [PMID: 28808140 DOI: 10.1096/fj.201700431r] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/25/2017] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease (AD) and type 2 diabetes (T2D) present a significant risk to each other. AD and T2D are characterized by deposition of cerebral amyloid-β (Aβ) and pancreatic human islet amyloid polypeptide (hIAPP), respectively. We investigated the role of amyloidogenic proteins in the interplay between these diseases. A novel double transgenic mouse model combining T2D and AD was generated and characterized. AD-related amyloid transgenic mice coexpressing hIAPP displayed peripheral insulin resistance, hyperglycemia, and glucose intolerance. Aβ and IAPP amyloid co-deposition increased tau phosphorylation, and a reduction in pancreatic β-cell mass was detected in islets. Increased brain Aβ deposition and tau phosphorylation and reduced insulin levels and signaling were accompanied by extensive synaptic loss and decreased neuronal counts. Aβ immunization rescued the peripheral insulin resistance and hyperglycemia, suggesting a role for Aβ in T2D pathogenesis for individuals predisposed to AD. These findings demonstrate that Aβ and IAPP are key factors in the overlapping pathologies of AD and T2D.-Wijesekara, N., Ahrens, R., Sabale, M., Wu, L., Ha, K., Verdile, G., Fraser, P. E. Amyloid-β and islet amyloid pathologies link Alzheimer's disease and type 2 diabetes in a transgenic model.
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Affiliation(s)
- Nadeeja Wijesekara
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada;
| | - Rosemary Ahrens
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Miheer Sabale
- School of Biomedical Sciences, Curtin Health and Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Ling Wu
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Kathy Ha
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Giuseppe Verdile
- School of Biomedical Sciences, Curtin Health and Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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Wijesekara N, Ahrens R, Wu L, Ha K, Liu Y, Wheeler MB, Fraser PE. Islet amyloid inhibitors improve glucose homeostasis in a transgenic mouse model of type 2 diabetes. Diabetes Obes Metab 2015; 17:1003-6. [PMID: 26095311 DOI: 10.1111/dom.12529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 06/03/2015] [Accepted: 06/14/2015] [Indexed: 11/29/2022]
Abstract
Increasing evidence points to the cytotoxicity of islet amyloid polypeptide (IAPP) aggregates as a major contributor to the loss of β-cell mass in type 2 diabetes. Prevention of IAPP formation represents a potential treatment to increase β-cell survival and function. The IAPP inhibitory peptide, D-ANFLVH, has been previously shown to prevent islet amyloid accumulation in cultured human islets. To assess its activity in vivo, D-ANFLVH was administered by intraperitoneal injection into a human IAPP transgenic mouse model, which replicates type 2 diabetes islet amyloid pathology. The peptide was a potent inhibitor of islet amyloid deposition, resulting in reduced islet cell apoptosis and preservation of β-cell area leading to improved glucose tolerance. These findings provide support for a key role of islet amyloid in β-cell survival and validate the application of anti-amyloid compounds as therapeutic strategies to maintain normal insulin secretion in patients with type 2 diabetes.
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Affiliation(s)
- N Wijesekara
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - R Ahrens
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - L Wu
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - K Ha
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Y Liu
- Department of Physiology, University of Toronto, Toronto, Canada
| | - M B Wheeler
- Department of Physiology, University of Toronto, Toronto, Canada
| | - P E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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Barth J, Ahrens R, Schaufelberger M. Consequences of insecurity in emergency telephone consultations: an experimental study in medical students. Swiss Med Wkly 2014; 144:w13919. [PMID: 24706369 DOI: 10.4414/smw.2014.13919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
QUESTION UNDER STUDY Handling emergency telephone consultations (ETCs) is a challenging and very important task for doctors. The aims of the study were to document insecurity in medical students during ETCs and to identify the reasons for that insecurity. We hypothesised that insecurity is associated with advising more urgent action (e.g. advice to call for an ambulance) in ETCs. METHODS We used ETCs with simulated patients (SPs), with each student randomly allocated two of four possible cases. After the training, 137 students reported on any insecurity that they had in the various ETC phases. We analysed the reasons for insecurity using descriptive statistics. The association between the students' advice that urgent action was needed and their insecurity was analysed with Spearman rank correlation. RESULTS Overall, 95% of the students felt insecure in at least one phase of their ETC. History taking was the phase in which students felt most insecure (63.1%), followed by the phase of analysing the information given by the patient (44.9%). Perceived insecurity was associated with more urgent advice in one case scenario (abdominal pain; correlation r = 0.46; p <0.01). The other two cases (child with fever; chest pain) also had a positive, but not statistically significant, correlation trend (p <0.12; p <0.08). CONCLUSIONS Insecurity is highly prevalent among medical students in their ETC decision-making. ETC training in medical schools, with a focus on structured history taking and formulating discriminating questions, might help decrease insecurity in ETCs. Medical education should also teach management of insecurity.
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Affiliation(s)
- J Barth
- Institute of Social and Preventive Medicine (ISPM), University of Bern, SWITZERLAND;
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Kreppenhofer K, Kim C, Schneider M, Herrmann D, Ahrens R, Kashef J, Gradl D, Wedlich D, Guber A. Microfluidic polycarbonate chip for long-term cell analyses. BIOMED ENG-BIOMED TE 2012. [DOI: 10.1515/bmt-2012-4429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rajabi T, Huck V, Ahrens R, Apfel MC, Kim SE, Schneider SW, Guber AE. Development of a novel two-channel microfluidic system for biomedical applications in cancer research. ACTA ACUST UNITED AC 2012. [DOI: 10.1515/bmt-2012-4029] [Citation(s) in RCA: 4] [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] [Indexed: 11/15/2022]
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Smukler SR, Arntfield ME, Razavi R, Bikopoulos G, Karpowicz P, Seaberg R, Dai F, Lee S, Ahrens R, Fraser PE, Wheeler MB, van der Kooy D. The adult mouse and human pancreas contain rare multipotent stem cells that express insulin. Cell Stem Cell 2011; 8:281-93. [PMID: 21362568 DOI: 10.1016/j.stem.2011.01.015] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 08/20/2010] [Accepted: 01/18/2011] [Indexed: 12/17/2022]
Abstract
The search for putative precursor cells within the pancreas has been the focus of extensive research. Previously, we identified rare pancreas-derived multipotent precursor (PMP) cells in the mouse with the intriguing capacity to generate progeny in the pancreatic and neural lineages. Here, we establish the embryonic pancreas as the developmental source of PMPs through lineage-labeling experiments. We also show that PMPs express insulin and can contribute to multiple pancreatic and neural cell types in vivo. In addition, we have isolated PMPs from adult human islet tissue that are also capable of extensive proliferation, self-renewal, and generation of multiple differentiated pancreatic and neural cell types. Finally, both mouse and human PMP-derived cells ameliorated diabetes in transplanted mice. These findings demonstrate that the adult mammalian pancreas contains a population of insulin(+) multipotent stem cells and suggest that these cells may provide a promising line of investigation toward potential therapeutic benefit.
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Affiliation(s)
- Simon R Smukler
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Groschwitz K, Ahrens R, Osterfeld H, Finkelman F, Rothenberg M, Abrink M, Pejler G, Hogan S. Mast Cell Chymase Regulates Homeostatic Intestinal Barrier Function. J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ahrens R, Osterfeld H, Finkelman F, Hogan S. Experimental Food Antigen- Life-threatening (FALT)-anaphylaxis Is Mediated By IgE-dependent Pathways. J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Osterfeld H, Ahrens R, Wu D, Forbes E, Finkelman F, Renauld J, Hogan S. Dissection Of The Role Of Il-9/il-9r-pathway In Murine Systemic And Intestinal Anaphylaxis. J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Groschwitz K, Forbes E, Brandt E, Ahrens R, Finkelman F, Abonia P, Rothenberg M, Hogan S. Intestinal Expression of Interleukin 9 (IL-9) Induces Mast Cell-Mediated Intestinal Permeability. J Allergy Clin Immunol 2007. [DOI: 10.1016/j.jaci.2006.12.594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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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Wang Q, Ahrens R, Dutta N. Optical gain of single mode short Er/Yb doped fiber. Opt Express 2004; 12:6192-6197. [PMID: 19488263 DOI: 10.1364/opex.12.006192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Optical gain and output power as a function of pump power has been calculated for short Er/Yb doped single mode fibers for various fiber parameters. The calculation shows that long fiber lengths provide both higher small signal gain and higher output power. Gain of 14 dB has been observed in a 30 mm long fiber at 400 mW of input pump power. The observed small signal gain is found to be linearly proportional to the length of the fiber with a slope of 0.44 dB/mm at 400 mW of pump power.
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Drisaldi B, Coomaraswamy J, Mastrangelo P, Strome B, Yang J, Watts JC, Chishti MA, Marvi M, Windl O, Ahrens R, Major F, Sy MS, Kretzschmar H, Fraser PE, Mount HTJ, Westaway D. Genetic Mapping of Activity Determinants within Cellular Prion Proteins. J Biol Chem 2004; 279:55443-54. [PMID: 15459186 DOI: 10.1074/jbc.m404794200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [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
The PrP-like Doppel (Dpl) protein causes apoptotic death of cerebellar neurons in transgenic mice, a process prevented by expression of the wild type (wt) cellular prion protein, PrP(C). Internally deleted forms of PrP(C) resembling Dpl such as PrPDelta32-121 produce a similar PrP(C)-sensitive pro-apoptotic phenotype in transgenic mice. Here we demonstrate that these phenotypic attributes of wt Dpl, wt PrP(C), and PrPDelta132-121 can be accurately recapitulated by transfected mouse cerebellar granule cell cultures. This system was then explored by mutagenesis of the co-expressed prion proteins to reveal functional determinants. By this means, neuroprotective activity of wt PrP(C) was shown to be nullified by a deletion of the N-terminal charged region implicated in endocytosis and retrograde axonal transport (PrPDelta23-28), by deletion of all five octarepeats (PrPDelta51-90), or by glycine replacement of four octarepeat histidine residues required for selective binding of copper ions (Prnp"H/G"). In the case of Dpl, overlapping deletions defined a requirement for the gene interval encoding helices B and B' (DplDelta101-125). These data suggest contributions of copper binding and neuronal trafficking to wt PrP(C) function in vivo and place constraints upon current hypotheses to explain Dpl/PrP(C) antagonism by competitive ligand binding. Further implementation of this assay should provide a fuller understanding of the attributes and subcellular localizations required for activity of these enigmatic proteins.
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Affiliation(s)
- Bettina Drisaldi
- Centre for Research in Neurodegenerative Diseases, Tanz Neuroscience Building, 6 Queen's Park Crescent West, University of Toronto, Toronto, Ontario M5S 3H2, Canada
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Stern RC, Eisenberg JD, Wagener JS, Ahrens R, Rock M, doPico G, Orenstein DM. A comparison of the efficacy and tolerance of pancrelipase and placebo in the treatment of steatorrhea in cystic fibrosis patients with clinical exocrine pancreatic insufficiency. Am J Gastroenterol 2000; 95:1932-8. [PMID: 10950038 DOI: 10.1111/j.1572-0241.2000.02244.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The safety and efficacy of Minimicrospheres, which are enteric-coated, delayed-release pancrelipase capsules, on fat absorption in pediatric/adolescent and adult cystic fibrosis (CF) patients was assessed. Exocrine pancreatic insufficiency, common in CF patients, causes steatorrhea due to insufficient release of pancreatic enzymes. METHODS In the open-label phase, 97 CF patients with pancreatic insufficiency and steatorrhea were stabilized on a high-fat diet and administered pancrelipase. Seventy-four patients with >80% coefficient of fat absorption received placebo or pancrelipase in the double-blind phase. Fat intake and excretion, stool frequency and consistency, and clinical global improvement were recorded. RESULTS Average daily fat intake was comparable between treatment groups within each age group (adults vs pediatric/adolescent), but placebo patients had a significant (p < 0.001) mean decrease in coefficient of fat absorption (adult, 36.9 percentage points; pediatric/adolescent, 34.9 percentage points) from open-label to double-blind treatment compared to pancrelipase patients (adult, 2 percentage points; pediatric/adolescent, 3.25 percentage points); this difference was caused by a greater (p < or = 0.001) increase in mean fecal fat excretion (grams per day) in the placebo groups compared to pancrelipase groups (adult: 61.9 vs 2.3; pediatric/adolescent: 45.4 vs 4.1). Change in mean stool frequency from open-label to double-blind phases was significantly different (p < or = 0.002) between treatment groups, with increases in placebo groups and no difference (adult) or decrease (pediatric/adolescent) in pancrelipase groups. Pancrelipase patients' stool consistency remained about the same from open-label to double-blind. Placebo patients' stool consistency decreased (became softer) from open-label pancrelipase to double-blind placebo. Clinical global improvement data showed that > or =83% of pancrelipase patients improved or remained unchanged. CONCLUSIONS Enteric-coated, delayed-release (Minimicrospheres) pancrelipase capsules are an effective treatment for steatorrhea associated with pancreatic insufficiency in patients with cystic fibrosis.
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Affiliation(s)
- R C Stern
- Rainbow Babies & Children's Hospital, Cleveland, Ohio 44106, USA
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Ahrens R. [Thinking--feeling--caring: experiences with intuitive, practical and theoretical knowledge of nursing]. Pflege Z 2000; 53:91-4. [PMID: 10797749] [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: 02/16/2023]
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27
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Geoffroy P, Lalonde RL, Ahrens R, Clarke W, Hill MR, Vaughan LM, Grossman J. Clinical comparability of albuterol delivered by the breath-actuated inhaler (Spiros) and albuterol by MDI in patients with asthma. Ann Allergy Asthma Immunol 1999; 82:377-82. [PMID: 10227336 DOI: 10.1016/s1081-1206(10)63287-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 11/25/2022]
Abstract
STUDY OBJECTIVE This study compares the efficacy and safety of one and two actuations of albuterol sulfate powder delivered via a breath-actuated, effort-assisted, investigational inhaler (Spiros, Dura Pharmaceuticals, Inc) and albuterol delivered via a conventional propellant-driven metered dose inhaler (Ventolin, Glaxo, Inc). DESIGN Randomized, double-blind, placebo-controlled, 5-way crossover study. PARTICIPANTS Sixty patients with mild-to-moderate asthma (FEV1 59% predicted) were enrolled and 44 completed the study. MEASUREMENTS AND RESULTS FEV1 values over 6 hours were analyzed by ANCOVA and the Finney relative potency model. The relative potency of the inhalers (albuterol MDI: albuterol DPI) was 1.132 (90% CI, 0.680 to 2.252) indicating 1.132 actuations of albuterol MDI provided the same bronchodilation as one actuation of albuterol DPI. ANCOVA analyses further indicated that there were no significant differences between the two delivery systems with respect to FEV1, FVC, FEF25-75%, or PEF. Both inhalers had similar effects on serum potassium levels, QTc interval, blood pressure, and heart rate. CONCLUSIONS In patients with mild-to-moderate asthma in this study, the albuterol DPI was determined to be therapeutically comparable to albuterol MDI in the delivery of one and two actuations of albuterol.
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Affiliation(s)
- P Geoffroy
- Phoenix International Life Sciences, Montreal, Quebec, Canada
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Ahrens R, Lux C, Bahl T, Han SH. Choosing the metered-dose inhaler spacer or holding chamber that matches the patient's need: evidence that the specific drug being delivered is an important consideration. J Allergy Clin Immunol 1995; 96:288-94. [PMID: 7636073 DOI: 10.1016/s0091-6749(95)70208-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- R Ahrens
- College of Medicine, Department of Pediatrics, University of Iowa, Iowa City, USA
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Balough K, McCubbin M, Weinberger M, Smits W, Ahrens R, Fick R. The relationship between infection and inflammation in the early stages of lung disease from cystic fibrosis. Pediatr Pulmonol 1995; 20:63-70. [PMID: 8570304 DOI: 10.1002/ppul.1950200203] [Citation(s) in RCA: 256] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We examined the relationship of pulmonary infection and inflammation in cystic fibrosis (CF) by performing 31 bronchoalveolar lavages (BAL) in 14 young children with minimal lung disease from CF. While 10 of the 14 patients had elevated polymorphonuclear leukocyte (PMN) counts initially, only 4 had bacteria generally regarded as pathogenic in the recovered BAL fluid. Three of these 4 and 6 of the others had follow-up bronchoscopies at 6 months intervals. PMN counts remained normal for only one patient. However, pathogenic bacteria were recovered during the repeat BALs only in those patients who were colonized initially. Proinflammatory cytokines and proteinases were generally elevated, and interleukin-8 (IL-8) concentration correlated inversely with oxygen saturation (SaO2). No complications of the procedure occurred. We conclude that BAL identifies inflammation and the presence of bacteria in the lower airway at an early stage of the disease. This information may be used to guide therapy in patients too young or otherwise unable to produce sputum. These data also suggest that inflammation is present early in the course of CF lung disease before colonization and infection of the lungs with potentially pathogenic bacteria occurs. Since inflammation appears to be the earliest detectable evidence of lung disease in CF, monitoring of inflammation with BAL may serve as a useful marker of clinical benefits from new treatments in patients with minimal lung disease.
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Affiliation(s)
- K Balough
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, USA
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McCubbin MM, Milavetz G, Grandgeorge S, Weinberger M, Ahrens R, Sargent C, Vaughan LM. A bioassay for topical and systemic effect of three inhaled corticosteroids. Clin Pharmacol Ther 1995; 57:455-60. [PMID: 7712675 DOI: 10.1016/0009-9236(95)90216-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [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: 01/26/2023]
Abstract
BACKGROUND Comparisons of relative potency for the three inhaled corticosteroids in the United States are limited to assessment of skin blanching. OBJECTIVE Development of a method for comparing relative potencies of inhaled corticosteroids for topical effect on human airway and systemic effect. METHODS With use of partial suppression of immediate response to inhaled allergen and 24-hour urinary free cortisol output, three-point dose-response curves were constructed for beclomethasone dipropionate (50 micrograms/puff), triamcinolone acetonide (100 micrograms/puff), and flunisolide (250 micrograms/puff). A randomized, parallel, single-blind study design was used. Dosing began with one puff four times a day for flunisolide and two puffs four times a day for the others. Doses were doubled after 1 week and again after a second week. RESULTS Twenty-five patients completed the study. Dose-response relationships were shown for each inhaled corticosteroid for both topical and systemic effect. Dose-response curves for the three preparations were similar when response was plotted against delivered dose in micrograms. CONCLUSION Within the limits of the assays, relative potencies of the three preparations appeared to be approximately equivalent for both topical and systemic effect when dose was expressed in micrograms. Relative potency per puff is therefore approximately proportional to the dose delivered. This method has potential for evaluation of relative potency of newer inhaled corticosteroids and the relative advantage of alternative delivery systems.
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Affiliation(s)
- M M McCubbin
- Pediatric Allergy and Pulmonary Division, College of Medicine, University of Iowa, USA
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Ahrens R. [Goethe's description of aphasia]. Nervenarzt 1993; 64:736-8. [PMID: 7506395] [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: 01/25/2023]
Affiliation(s)
- R Ahrens
- Niedersächsisches Psychiatrisches Landeskrankenhaus, Moringen-Göttingen
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Ahrens R, Ott M, Ritter A, Hoschützky H, Bühler T, Lottspeich F, Boulnois GJ, Jann K, Hacker J. Genetic analysis of the gene cluster encoding nonfimbrial adhesin I from an Escherichia coli uropathogen. Infect Immun 1993; 61:2505-12. [PMID: 8099066 PMCID: PMC280876 DOI: 10.1128/iai.61.6.2505-2512.1993] [Citation(s) in RCA: 27] [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] [Indexed: 01/28/2023] Open
Abstract
The chromosomally encoded nonfimbrial adhesion I (NFA-I) from Escherichia coli urinary tract isolate 827 (O83:K1:H4) mediates agglutination of human erythrocytes. Subclones were constructed from an NFA-I-expressing recombinant E. coli K-12 clone, derived from a genomic library of E. coli 827. Minicell analysis and nucleotide sequencing revealed that proteins of 30.5, 9, 80, 15, and 19 kDa encoded on a stretch of approximately 6 kb are involved in the expression of NFA-I. NFA-I exhibits a polymeric structure, which disintegrates with elevated temperature into a 19-kDa monomer but with some relatively stable dimers. By using gold-conjugated monoclonal antibodies directed against NFA-I in electron microscopy, the adhesin could be localized on the outer surface of the recombinant E. coli K-12 bacteria. The nucleotide sequence of the nfaA gene encoding the monomeric structural subunit of the adhesin was determined. An open reading frame of 184 amino acids encoding the NfaA precursor, which is processed to the mature protein, was found; it consisted of 156 amino acids with a calculated molecular weight of 16,000. Peptide sequencing of the NFA-I subunit protein confirmed that this open reading frame corresponds to the NfaA coding locus. Furthermore, the nucleotide sequence of the open reading frame termed NfaE, located at the proximal part of the DNA stretch responsible for NFA-I expression, was elaborated. NfaE consists of 247 amino acids, including a presumptive 29-amino-acid signal peptide, leading to a molecular weight of 24,000 for the mature protein. The nfaE sequence shares homology with the 27-kDa CS3 protein, which is involved in the assembly of CS3 fibrillae, and might encode the 30.5-kDa protein, detected in minicells.
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Affiliation(s)
- R Ahrens
- Max-Planck Institut für Immunbiologie, Freiburg
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Adelmann P, Ahrens R, Czjzek G, Roth G, Schmidt H, Steinleitner C. Structure and rare-earth magnetism in (Nd1-xGdx)2CuO4. Phys Rev B Condens Matter 1992; 46:3619-3630. [PMID: 10004079 DOI: 10.1103/physrevb.46.3619] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Balough K, Ahrens R. The cold war against RSV. Iowa Med 1991; 81:441-4. [PMID: 1765449] [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: 12/28/2022]
Abstract
Respiratory Syncytial Virus (RSV) can cause substantial morbidity and mortality in high risk patients. The authors discuss prevention and treatment of this virus.
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Affiliation(s)
- K Balough
- Pediatric Allergy and Pulmonary Division, University of Iowa Hospitals and Clinics
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Ahrens R, Jann B, Jann K, Brade H. Structure of the K74 antigen from Escherichia coli O44:K74:H18, a capsular polysaccharide containing furanosidic beta-KDO residues. Carbohydr Res 1988; 179:223-31. [PMID: 2850105 DOI: 10.1016/0008-6215(88)84120-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [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: 01/02/2023]
Abstract
The structure of the capsular K74 antigen of E. coli H702c (O44:K74:H18) was elucidated by determination of the composition, 1H- and 13C-n.m.r. and c.d. spectroscopy, periodate oxidation, and methylation analysis of the polysaccharide and of a trisaccharide obtained by mild acid hydrolysis. The K74 antigen has the repeating unit----3)-beta-D-Ribf-(1----2)-beta-D-Ribf-(1----6)-beta-++ +KDOf-(2----. Of the repeating units, approximately 65% are O-acetylated, most probably at C-2 of the 3-linked ribose.
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Affiliation(s)
- R Ahrens
- Max-Planck-Institut für Immunbiologie, Freiburg, F.R.G
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Affiliation(s)
- B Jann
- Max-Planck-Institut für Immunbiologie, Freiburg, F.R.G
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Massey KL, Hill M, Harman E, Rutledge DR, Ahrens R, Hendeles L. Dose response of inhaled gallopamil (D600), a calcium channel blocker, in attenuating airway reactivity to methacholine and exercise. J Allergy Clin Immunol 1988; 81:912-8. [PMID: 3286722 DOI: 10.1016/0091-6749(88)90950-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [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: 01/05/2023]
Abstract
To determine if there is a dose-response relationship for calcium channel blockers in preventing experimentally induced bronchoconstriction, we evaluated the effects of inhaled gallopamil (D600), a potent methoxy derivative of verapamil, on airway reactivity to methacholine and exercise in volunteers with mild asthma. Methacholine challenges were completed by 11 subjects 2 hours before and 20 minutes after placebo, and 1, 2, 5, 10, and 20 mg of inhaled gallopamil administered in a single-blind, randomized manner on different days. Gallopamil did not significantly alter FVC, FEV1, or forced expiratory flow rate between 25% and 75% of FVC, but increased the dose of methacholine required to produce a 20% decrease in FEV1 from baseline (p less than 0.0001). The mean +/- SEM fold increase in the dose of methacholine required to produce a 20% decrease in FEV1 from baseline was 1.0 +/- 0.1 after placebo, 2.4 +/- 0.2 after 1 mg, 2.2 +/- 0.2 after 2 mg, 2.5 +/- 0.2 after 5 mg, 2.5 +/- 0.3 after 10 mg, and 2.3 +/- 0.2 after 20 mg. Thirty minutes before a standardized exercise challenge, 10 subjects inhaled 1 and 10 mg of gallopamil or placebo in a randomized, double-blind, crossover manner. The mean +/- SEM maximum decrease in FEV1 after exercise was 25.1 +/- 5% after 10 mg of gallopamil (p less than 0.01), 34.4 +/- 5% after 1 mg (p greater than 0.05), and 39.0 +/- 6% after placebo. We conclude that inhaled gallopamil only modestly alters airway reactivity to methacholine; increasing the dose greater than 1 mg did not provide greater benefit.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K L Massey
- Department of Pharmacy Practice, College of Pharmacy, University of Florida, Gainesville 32610
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Ahrens R, Damon D, Isaac E, von Graevenitz A, Todorovich M, Wilson R. Radiation risks from nuclear power exaggerated. N Engl J Med 1980; 302:1205-6. [PMID: 7366665 DOI: 10.1056/nejm198005223022115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Spector R, Ahrens R. Dosing regimens in seriously ill patients. J Iowa Med Soc 1980; 70:61-3, 72. [PMID: 7354222] [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: 01/24/2023]
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Bodwell CE, Schuster EM, Kyle E, Brooks B, Womack M, Steele P, Ahrens R. Obligatory urinary and fecal nitrogen losses in young women, older men, and young men and the factorial estimation of adult human protein requirements. Am J Clin Nutr 1979; 32:2450-9. [PMID: 506969 DOI: 10.1093/ajcn/32.12.2450] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Obligatory urinary and fecal nitrogen losses and urinary urea nitrogen and creatinine excretion levels were determined in 11 young women (four of whom used oral contraceptives), eight older men, and five young men. Values for obligatory nitrogen losses in the young women who did not use oral contraceptives were similar to those observed previously in young women and lower than those reported for young men. Our values for older men were lower than previously reported values for obligatory losses observed in young and elderly men, but similar to previously reported values for young women and to values for our women who did not use oral contraceptives. The four oral contraceptive users had significantly higher levels of total urinary and fecal obligatory nitrogen losses than the nonusers in our study. When values from our study and values from other recent studies are considered, variations in obligatory nitrogen losses appear to be larger among individuals within an age-sex group than the observed differences between groups. When the intakes of protein recommended as safe by the Food aculated from obligatory nitrogen losses per se, the recommended levels appear to be only marginally adequate.
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Ahrens R. [Disturbances of word finding of compound nouns (nomina composita) in aphasics (author's transl)]. Arch Psychiatr Nervenkr (1970) 1977; 224:73-87. [PMID: 931598 DOI: 10.1007/bf00342086] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The faulty use of compound nouns by aphasics is of practical and theoretical significance. Defects in the finding and using of compound nouns were investigated with respect to the following parameters: the importance of the frequency with which compounds and compound parts are used in normal speech, the influence of grammatical and psycholinguistic peculiarities on aphasic dysfunction, and the handling of compounds in individual aphasic syndromes. The distinctly poorer recall of compound nouns compared with simple nouns was found to be due mainly to their less frequent use in normal speech. In word-finding the grammatical unit of the compound noun was not very stable patholinguistically. If one part of the compound noun was commoner and more usual in normal speech than the other it was usually better recalled. However, some remarkable deviations from this were due to semantic functional value, vividness, morphologic peculiarities, and linguistic form. The wider meaning-range of the second part of the compound noun had no positive mnemonic effect, despite the propensity of the aphasic for the general. In naming tests the first part of the compound noun was preferred on average. Certain differences in the defective use of compound nouns were observed between the individual aphasic syndromes.
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Ahrens R. [Effect of sublethal röntgen doses on the mitochondria of cultivated cells and simultaneous assay of Mg++-dependent adenosine triphosphatase]. Strahlentherapie 1972; 143:576-87. [PMID: 4262469] [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: 01/09/2023]
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Ahrens R. [Value of linguistics and psycholinguistics in the diagnostic and therapeutic dialogue]. Z Psychosom Med Psychoanal 1971; 17:294-318. [PMID: 5124708] [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: 01/13/2023]
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Ahrens R. On the forensic-psychiatric significance of alcohol loading tests under EEG control. Electroencephalogr Clin Neurophysiol 1971; 30:269-70. [PMID: 4103228] [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: 01/08/2023]
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Moll G, Ahrens R. [An unusually broad type of fimbria]. Arch Hyg Bakteriol 1969; 153:570-1. [PMID: 4195380] [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: 01/09/2023]
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Ahrens R, Weissenfels N. [Demonstration of adenosine triphosphatase in mitochondria of cultured chick cardiac myoblasts]. Histochemie 1969; 19:248-54. [PMID: 4242204 DOI: 10.1007/bf00305287] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Ahrens R. Modern Methods of Analysis of Copper and its Alloys. VonCh. M. Dozinel, übers. v.St. L. Man. Elsevier Publishing Co., Amsterdam-London-New York 1963. 2. Aufl., XVII, 287 S., 15 Abb., 36 Tab., geb. DM 44.50. Angew Chem Int Ed Engl 1964. [DOI: 10.1002/ange.19640761536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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