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Luvira V, Schilling WHK, Jittamala P, Watson JA, Boyd S, Siripoon T, Ngamprasertchai T, Almeida PJ, Ekkapongpisit M, Cruz C, Callery JJ, Singh S, Tuntipaiboontana R, Kruabkontho V, Ngernseng T, Tubprasert J, Abdad MY, Keayarsa S, Madmanee W, Aguiar RS, Santos FM, Hanboonkunupakarn P, Hanboonkunupakarn B, Poovorawan K, Imwong M, Taylor WRJ, Chotivanich V, Chotivanich K, Pukrittayakamee S, Dondorp AM, Day NPJ, Teixeira MM, Piyaphanee W, Phumratanaprapin W, White NJ. Clinical antiviral efficacy of favipiravir in early COVID-19 (PLATCOV): an open-label, randomised, controlled, adaptive platform trial. BMC Infect Dis 2024; 24:89. [PMID: 38225598 PMCID: PMC10789040 DOI: 10.1186/s12879-023-08835-3] [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: 03/10/2023] [Accepted: 11/21/2023] [Indexed: 01/17/2024] Open
Abstract
In early symptomatic COVID-19 treatment, high dose oral favipiravir did not accelerate viral clearance. BACKGROUND Favipiravir, an anti-influenza drug, has in vitro antiviral activity against SARS-CoV-2. Clinical trial evidence to date is inconclusive. Favipiravir has been recommended for the treatment of COVID-19 in some countries. METHODS In a multicentre open-label, randomised, controlled, adaptive platform trial, low-risk adult patients with early symptomatic COVID-19 were randomised to one of ten treatment arms including high dose oral favipiravir (3.6g on day 0 followed by 1.6g daily to complete 7 days treatment) or no study drug. The primary outcome was the rate of viral clearance (derived under a linear mixed-effects model from the daily log10 viral densities in standardised duplicate oropharyngeal swab eluates taken daily over 8 days [18 swabs per patient]), assessed in a modified intention-to-treat population (mITT). The safety population included all patients who received at least one dose of the allocated intervention. This ongoing adaptive platform trial was registered at ClinicalTrials.gov (NCT05041907) on 13/09/2021. RESULTS In the final analysis, the mITT population contained data from 114 patients randomised to favipiravir and 126 patients randomised concurrently to no study drug. Under the linear mixed-effects model fitted to all oropharyngeal viral density estimates in the first 8 days from randomisation (4,318 swabs), there was no difference in the rate of viral clearance between patients given favipiravir and patients receiving no study drug; a -1% (95% credible interval: -14 to 14%) difference. High dose favipiravir was well-tolerated. INTERPRETATION Favipiravir does not accelerate viral clearance in early symptomatic COVID-19. The viral clearance rate estimated from quantitative measurements of oropharyngeal eluate viral densities assesses the antiviral efficacy of drugs in vivo with comparatively few studied patients.
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Affiliation(s)
- Viravarn Luvira
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - William H K Schilling
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - James A Watson
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Simon Boyd
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tanaya Siripoon
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thundon Ngamprasertchai
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pedro J Almeida
- Clinical Research Unit, Center for Advanced and Innovative Therapies, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Maneerat Ekkapongpisit
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Cintia Cruz
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Shivani Singh
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Runch Tuntipaiboontana
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Varaporn Kruabkontho
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thatsanun Ngernseng
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jaruwan Tubprasert
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mohammad Yazid Abdad
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Srisuda Keayarsa
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wanassanan Madmanee
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Renato S Aguiar
- Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Franciele M Santos
- Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Borimas Hanboonkunupakarn
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kittiyod Poovorawan
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Walter R J Taylor
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Kesinee Chotivanich
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sasithon Pukrittayakamee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mauro M Teixeira
- Clinical Research Unit, Center for Advanced and Innovative Therapies, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Watcharapong Piyaphanee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Weerapong Phumratanaprapin
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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2
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Jittamala P, Schilling WHK, Watson JA, Luvira V, Siripoon T, Ngamprasertchai T, Almeida PJ, Ekkapongpisit M, Cruz C, Callery JJ, Boyd S, Anunsittichai O, Hongsuwan M, Singhaboot Y, Pagornrat W, Tuntipaiboontana R, Kruabkontho V, Ngernseng T, Tubprasert J, Abdad MY, Keayarsa S, Madmanee W, Aguiar RS, Santos FM, Batty EM, Hanboonkunupakarn P, Hanboonkunupakarn B, Sookprome S, Poovorawan K, Imwong M, Taylor WRJ, Chotivanich V, Sangketchon C, Ruksakul W, Chotivanich K, Pukrittayakamee S, Dondorp AM, Day NPJ, Teixeira MM, Piyaphanee W, Phumratanaprapin W, White NJ. Clinical Antiviral Efficacy of Remdesivir in Coronavirus Disease 2019: An Open-Label, Randomized Controlled Adaptive Platform Trial (PLATCOV). J Infect Dis 2023; 228:1318-1325. [PMID: 37470445 PMCID: PMC10640773 DOI: 10.1093/infdis/jiad275] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 02/20/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Uncertainty over the therapeutic benefit of parenteral remdesivir in coronavirus disease 2019 (COVID-19) has resulted in varying treatment guidelines. METHODS In a multicenter open-label, controlled, adaptive, pharmacometric platform trial, low-risk adult patients with early symptomatic COVID-19 were randomized to 1 of 8 treatment arms including intravenous remdesivir (200 mg followed by 100 mg daily for 5 days) or no study drug. The primary outcome was the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance (estimated under a linear model fit to the daily log10 viral densities, days 0-7) in standardized duplicate oropharyngeal swab eluates, in a modified intention-to-treat population. This ongoing adaptive trial is registered at ClinicalTrials.gov (NCT05041907). RESULTS The 2 study arms enrolled 131 patients (remdesivir n = 67, no study drug n = 64) and estimated viral clearance rates from a median of 18 swab samples per patient (a total of 2356 quantitative polymerase chain reactions). Under the linear model, compared with the contemporaneous control arm (no study drug), remdesivir accelerated mean estimated viral clearance by 42% (95% credible interval, 18%-73%). CONCLUSIONS Parenteral remdesivir accelerates viral clearance in early symptomatic COVID-19. Pharmacometric assessment of therapeutics using the method described can determine in vivo clinical antiviral efficacy rapidly and efficiently.
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Affiliation(s)
- Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - William H K Schilling
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - James A Watson
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Viravarn Luvira
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Tanaya Siripoon
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thundon Ngamprasertchai
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pedro J Almeida
- Clinical Research Unit, Centre for Advanced and Innovative Therapies, Belo Horizonte, Brazil
| | | | - Cintia Cruz
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Simon Boyd
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | - Yutatirat Singhaboot
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | | | | | | | | | - Mohammad Yazid Abdad
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Srisuda Keayarsa
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Renato S Aguiar
- Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Franciele M Santos
- Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Elizabeth M Batty
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sakol Sookprome
- Bangplee Hospital, Ministry of Public Health, Samut Prakarn, Thailand
| | - Kittiyod Poovorawan
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Walter R J Taylor
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Chunlanee Sangketchon
- Faculty of Science and Health Technology, Navamindradhiraj University, Bangkok, Thailand
| | - Wiroj Ruksakul
- Faculty of Medicine, Navamindradhiraj University, Bangkok, Thailand
| | - Kesinee Chotivanich
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sasithon Pukrittayakamee
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mauro M Teixeira
- Clinical Research Unit, Centre for Advanced and Innovative Therapies, Belo Horizonte, Brazil
| | - Watcharapong Piyaphanee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Weerapong Phumratanaprapin
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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3
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Queiroz-Junior CM, Santos ACPM, Gonçalves MR, Brito CB, Barrioni B, Almeida PJ, Gonçalves-Pereira MH, Silva T, Oliveira SR, Pereira MM, Santiago HC, Teixeira MM, Costa VV. Acute coronavirus infection triggers a TNF-dependent osteoporotic phenotype in mice. Life Sci 2023; 324:121750. [PMID: 37142087 PMCID: PMC10152759 DOI: 10.1016/j.lfs.2023.121750] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 02/22/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/06/2023]
Abstract
AIMS Millions of people died during the COVID-19 pandemic, but the vast majority of infected individuals survived. Now, some consequences of the disease, known as long COVID, are been revealed. Although the respiratory system is the target of Sars-CoV-2, COVID-19 can influence other parts of the body, including bone. The aim of this work was to investigate the impact of acute coronavirus infection in bone metabolism. MAIN METHODS We evaluated RANKL/OPG levels in serum samples of patients with and without acute COVID-19. In vitro, the effects of coronavirus in osteoclasts and osteoblasts were investigated. In vivo, we evaluated the bone phenotype in a BSL2 mouse model of SARS-like disease induced by murine coronavirus (MHV-3). KEY FINDINGS Patients with acute COVID-19 presented decreased OPG and increased RANKL/OPG ratio in the serum versus healthy individuals. In vitro, MHV-3 infected macrophages and osteoclasts, increasing their differentiation and TNF release. Oppositely, osteoblasts were not infected. In vivo, MHV-3 lung infection triggered bone resorption in the femur of mice, increasing the number of osteoclasts at 3dpi and decreasing at 5dpi. Indeed, apoptotic-caspase-3+ cells have been detected in the femur after infection as well as viral RNA. RANKL/OPG ratio and TNF levels also increased in the femur after infection. Accordingly, the bone phenotype of TNFRp55-/- mice infected with MHV-3 showed no signs of bone resorption or increase in the number of osteoclasts. SIGNIFICANCE Coronavirus induces an osteoporotic phenotype in mice dependent on TNF and on macrophage/osteoclast infection.
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Affiliation(s)
- Celso M Queiroz-Junior
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Anna C P M Santos
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Matheus R Gonçalves
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Camila B Brito
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Breno Barrioni
- Institute of Engineering, Science and Technology, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Janaúba, MG, Brazil
| | - Pedro J Almeida
- Medical School, Ciências da Saúde: Infectologia e Medicina Tropical, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marcela H Gonçalves-Pereira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Tarcília Silva
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Sicília R Oliveira
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marivalda M Pereira
- Department of Metallurgical Engineering and Materials, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Helton C Santiago
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Mauro M Teixeira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vivian V Costa
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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4
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Sousa MBT, Santos JR, Almeida PJ, Rodrigues JA. Low pressure ion pair chromatography with amperometric detection for the determination of trigonelline in coffee samples. Food Res Int 2018; 114:223-229. [PMID: 30361020 DOI: 10.1016/j.foodres.2018.07.068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/06/2018] [Accepted: 07/31/2018] [Indexed: 11/17/2022]
Abstract
In this work, the use of ion pair chromatography strategy in low pressure chromatographic flow systems is explored for the first time. The straightforward flow manifold encompassed a peristaltic pump, an injection valve and a 1 cm-length C18 monolithic column. The amperometric detection system relied on a boron-doped diamond electrode, used as working electrode. The determination of trigonelline in coffee samples was the case-study selected. This alkaloid is an important quality marker for this commodity and is usually determined using HPLC-UV methodologies. The proposed methodology, based on ion-pair chromatography with amperometric detection, enabled the quantitative resolution of the studied analyte from the matrix compounds by adding to the mobile phase the ion pair reagent, 1-tetradecanosulfonate sodium. The present work, following the recent developments of the low pressure chromatography approach, demonstrates the potentialities of coupling monolithic columns to traditional flow analysis systems for separation and quantification of ionic or ionisable compounds.
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Affiliation(s)
- Manuela B T Sousa
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - João Rodrigo Santos
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
| | - P J Almeida
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - J A Rodrigues
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
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Parmigiani F, Petropoulos P, Ibsen M, Almeida PJ, Ng TT, Richardson DJ. Time domain add-drop multiplexing scheme enhanced using a saw-tooth pulse shaper. Opt Express 2009; 17:8362-8369. [PMID: 19434169 DOI: 10.1364/oe.17.008362] [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] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We experimentally demonstrate the use of saw-tooth optical pulses, which are shaped using a fiber Bragg grating, to achieve robust and high performance time-domain add-drop multiplexing in a scheme based on cross-phase (XPM) modulation in an optical fiber, with subsequent offset filtering. As compared to the use of more conventional pulse shapes, such as Gaussian pulses of a similar pulse width, the purpose-shaped saw-tooth pulses allow higher extinction ratios for the add and drop windows and significant improvements in the receiver sensitivity for the dropped and added channels.
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Affiliation(s)
- F Parmigiani
- Optoelectronics Research Centre, University of Southampton, Southampton, United Kingdom.
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Guido LF, Carneiro JR, Santos JR, Almeida PJ, Rodrigues JA, Barros AA. Simultaneous determination of E-2-nonenal and β-damascenone in beer by reversed-phase liquid chromatography with UV detection. J Chromatogr A 2004; 1032:17-22. [PMID: 15065771 DOI: 10.1016/j.chroma.2003.12.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [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: 11/20/2022]
Abstract
A method for the simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography using UV detection is presented. The method consists of beer steam distillation, followed by an extraction/concentration step using Sep-Pak Plus C18 RP cartridges and determination by HPLC at 226 nm UV-absorption maximum. The identity of the compounds was confirmed by GC analysis with MS detection of the isolated fractions. A recovery factor of approximately 80% was obtained for beta-damascenone with a R.S.D. of 3%. E-2-Nonenal and beta-damascenone were monitored in a comparative study of fresh and either naturally and forced aged beer. The results obtained show that both compounds have a similar behaviour through an extended storage of beer and consequently can be used as good analytical markers of beer ageing. Nevertheless, the use of beta-damascenone seems to be more convenient because this compound appears in beer in higher concentrations than E-2-nonenal, thus making it easier to measure.
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Affiliation(s)
- L F Guido
- Departamento de Química, Faculdade de Ciências, Centro de Investigação em Química da Universidade do Porto, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
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7
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Santos JR, Carneiro JR, Guido LF, Almeida PJ, Rodrigues JA, Barros AA. Determination of E-2-nonenal by high-performance liquid chromatography with UV detection assay for the evaluation of beer ageing. J Chromatogr A 2003; 985:395-402. [PMID: 12580508 DOI: 10.1016/s0021-9673(02)01396-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [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
The analysis of E-2-nonenal is of considerable interest for the brewery industry as this compound is claimed to be responsible for a paper/cardboard unpleasant flavour. Usually, the presence of E-2-nonenal can be noticed in aged beers at levels higher than 0.1 microg/l. In this work, an analytical method was developed to determine E-2-nonenal in beer involving steam distillation of beer followed by an extraction/concentration step using solid-phase extraction and determination of E-2-nonenal by HPLC with UV detection. Fastness and simplicity are the main advantages of the proposed method, when compared with other existing methodologies for the determination of E-2-nonenal in beer. Using the developed conditions, the interference of E-2-nonenal formed by degradation of its precursors during steam distillation is almost negligible. The presence of sulphur dioxide at legal levels does not interfere with the assay. The method was used in a comparative study of fresh and either naturally or forced aged beers. A much larger chromatographic peak was found near the peak of E-2-nonenal that correlates well with the peak of E-2-nonenal. Identification of the corresponding compound is currently under investigation, considering its future application on the evaluation of beer ageing.
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Affiliation(s)
- J R Santos
- Centro de Investigação em Química da Universidade do Porto. Departamento de Química da Faculdade de Ciências do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal
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Almeida PJ, Bissoli NS, Carvalhinho FB, Cabral AM. Endothelium-dependent and endothelium-independent effects of adenosine diphosphate in renovascular hypertension. Hypertension 1992; 19:II224-30. [PMID: 1735585 DOI: 10.1161/01.hyp.19.2_suppl.ii224] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Norepinephrine-induced responses in isolated perfused mesenteric vascular bed from normotensive and renovascular hypertensive rats were examined in the presence of adenosine diphosphate (ADP, 2 x 10(-6) M). Responses to norepinephrine were significantly greater in vessels from hypertensive rats. Norepinephrine-induced contractions increased after the removal of endothelium. N omega-Nitro-L-arginine (L-NOARG), a potent inhibitor of nitric oxide formation, similarly increased contractions. The greatest responses were obtained, however, after treatment of the vascular segments with methylene blue. The presence of ADP caused significant endothelium-dependent decreases in contractions. Although decreases caused by ADP in vessels with endothelium after treatment with L-NOARG were not statistically significant, a tendency to decreased responses seems to suggest that L-NOARG diminishes but does not completely prevent the effect of ADP in mesenteric vessels. Methylene blue partially reduced the endothelium-dependent ADP-induced relaxant effects in sham-operated nephrectomized rats. A tendency to increased contractions to norepinephrine was observed in the presence of ADP after removal of endothelium. Thus, in the mesenteric resistance arteries of the rat under stimulation by ADP, it appears that nitric oxide released from L-arginine and the activity of soluble guanylate cyclase account only in part for the endothelium-dependent decreased responses to norepinephrine. When nitric oxide formation or soluble guanylate cyclase activity are depressed simultaneously with endothelium damage, ADP released from platelets or red blood cells may be an important factor that acts synergically with vasoconstrictor stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P J Almeida
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitoria, Brazil
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Vassallo DV, Prates TM, Almeida PJ. [Inotropic effects of a verapamil and propranolol combination]. Arq Bras Cardiol 1977; 30 Suppl 1:23-6. [PMID: 889472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Alvarado LG, Costa AL, Giarnordoli B, Borges GR, Almeida PJ, Rios W, Rodrigues I. [Diagnostic importance of angiocardiography. Initial experience]. Arq Bras Cardiol 1969; 22:243-50. [PMID: 5360671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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