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Peretti-Watel P, Fressard L, Giry B, Verger P, Ward JK. Social Stigma and COVID-19 Vaccine Refusal in France. JOURNAL OF HEALTH POLITICS, POLICY AND LAW 2024; 49:567-598. [PMID: 38324348 DOI: 10.1215/03616878-11186095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
CONTEXT In 2021, French health authorities strongly promoted vaccination against COVID-19. The authors assumed that refusing this vaccine became a stigma, and they investigated potential public stigma toward unvaccinated people among the French population. METHODS A representative sample of the French adult population (N = 2,015) completed an online questionnaire in September 2021. The authors focused on participants who were already vaccinated against COVID-19 or intended to get vaccinated (N = 1,742). A cluster analysis was used to obtain contrasted attitudinal profiles, and the authors investigated associated factors with logistic regressions. FINDINGS Regarding attitudes toward unvaccinated people, a majority of respondents supported several pejorative statements, and a significant minority also endorsed social rejection attitudes. The authors found four contrasting attitudinal profiles: moral condemnation only (32% of respondents), full stigma (26%), no stigma (26%), and stigma rejection (16%). Early vaccination, civic motives for it, faith in science, rejection of political extremes, and being aged 65 or older were the main factors associated with stigmatizing attitudes toward unvaccinated people. CONCLUSIONS The authors found some evidence of stigmatization toward unvaccinated people, but further research is needed, especially to investigate perceived stigmatization among them. The authors discuss their results with reference to the concept of "folk devils" and from a public health perspective.
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Zhao R, Xia Z, Ke M, Lv J, Zhong H, He Y, Gu D, Liu Y, Zeng G, Zhu L, Alexoff D, Kung HF, Wang X, Sun T. Determining the optimal pharmacokinetic modelling and simplified quantification method of [ 18F]AlF-P16-093 for patients with primary prostate cancer (PPCa). Eur J Nucl Med Mol Imaging 2024; 51:2124-2133. [PMID: 38285206 DOI: 10.1007/s00259-024-06624-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/20/2024] [Indexed: 01/30/2024]
Abstract
PURPOSE This paper discusses the optimization of pharmacokinetic modelling and alternate simplified quantification method for [18F]AlF-P16-093, a novel tracer for in vivo imaging of prostate cancer. METHODS Dynamic PET/CT scans were conducted on eight primary prostate cancer patients, followed by a whole-body scan at 60 min post-injection. Time-activity curves (TACs) were obtained by drawing volumes of interest for primary prostatic and metastatic lesions. Optimal kinetic modelling involved evaluating three compartmental models (1T2K, 2T3K, and 2T4K) accounting for fractional blood volume (Vb). The simplified quantification method was then determined based on the correlation between the static uptake measure and total distribution volume (Vt) obtained from the optimal pharmacokinetic analysis. RESULTS In total, 17 intraprostatic lesions, 10 lymph nodes, and 36 osseous metastases were evaluated. Visually, the contrast of the tumor increased and showed the steepest incline within the first few minutes, whereas background activity decreased over time. Full pharmacokinetic analysis revealed that a reversible two-compartmental (2T4K) model is the preferred kinetic model for the given tracer. The kinetic parameters K1, k3, Vb, and Vt were all significantly higher in lesions when compared with normal tissue (P < 0.01). Several simplified protocols were tested for approximating comprehensive dynamic quantification in tumors, with image-based SURmean (the ratio of tumor SUVmean to blood SUVmean) within the 28-34 min window found to be sufficient for approximating the total distribution Vt values (R2 = 0.949, P < 0.01). Both Vt and SURmean correlated significantly with the total serum prostate-specific antigen (tPSA) levels (P < 0.01). CONCLUSIONS This study introduced an optimized pharmacokinetic modelling approach and a simplified acquisition method for [18F]AlF-P16-093, a novel PSMA-targeted radioligand, highlighting the feasibility of utilizing one static PET imaging (between 30 and 60 min) for the diagnosis of prostate cancer. Note that the image-derived input function in this study may not reflect the true corrected plasma input function, therefore the interpretation of the associated kinetic parameter estimates should be done with caution.
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Affiliation(s)
- Ruiyue Zhao
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
| | - Zeheng Xia
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, Guangdong, China
| | - Miao Ke
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
| | - Jie Lv
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
| | - Huizhen Zhong
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
| | - Yulu He
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
| | - Di Gu
- Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510230, Guangdong, China
| | - Yongda Liu
- Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510230, Guangdong, China
| | - Guohua Zeng
- Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510230, Guangdong, China
| | - Lin Zhu
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China
- College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - David Alexoff
- Five Eleven Pharma Inc., 3700 Market St., Philadelphia, PA, 19104, USA
| | - Hank F Kung
- Five Eleven Pharma Inc., 3700 Market St., Philadelphia, PA, 19104, USA
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Xinlu Wang
- Department of Nuclear Medicine, The Key Laboratory of Advanced Interdisciplinary Studies Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China.
| | - Tao Sun
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, Guangdong, China.
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Bacigalupe LD, Solano‐Iguaran JJ, Longo AV, Gaitán‐Espitia JD, Valenzuela‐Sánchez A, Alvarado‐Rybak M, Azat C. Nor climate nor human impact factors: Chytrid infection shapes the skin bacterial communities of an endemic amphibian in a biodiversity hotspot. Ecol Evol 2024; 14:e11249. [PMID: 38590552 PMCID: PMC10999949 DOI: 10.1002/ece3.11249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
The bacterial communities of the amphibian skin (i.e., the bacteriome) are critical to the host's innate immune system. However, it is unclear how different drivers can alter this function by modulating the bacteriome's structure. Our aim was to assess the extent to which different host attributes and extrinsic factors influence the structure of the bacterial communities of the skin. Skin bacterial diversity was examined in 148 individuals of the four-eyed frog (Pleurodema thaul) from 16 localities spanning almost 1800 km in latitude. The richness and beta diversity of bacterial families and the richness and abundance of Bd-inhibitory bacterial genera were used to describe their structure. Predictors associated with the host (developmental stage, genetic lineage, individual Batrachochytrium dendrobatidis [Bd] infection status) and the landscape (current climate, degree of anthropogenic disturbance) were used in the statistical modeling in an information theoretical approach. Bd infection and host developmental stage were the only predictors affecting bacteriome richness, with Bd+ individuals and postmetamorphic stages (adults and juveniles) having higher richness than Bd- ones and tadpoles. High diversity in Bd+ individuals is not driven by bacterial genera with known anti-Bd properties. Beta diversity was not affected by Bd infection and was mainly a consequence of bacterial family turnover rather than nestedness. Finally, for those bacterial genera known to have inhibitory effects on chytrid, Bd+ individuals had a slightly higher diversity than Bd- ones. Our study confirms an association between Bd infection and the host developmental stage with the bacterial communities of the skin of P. thaul. Unexpectedly, macroclimate and human impact factors do not seem to play a role in shaping the amphibian skin microbiome. Our study exemplifies that focusing on a single host-parasite system over a large geographic scale can provide essential insights into the factors driving host-parasite-bacteriome interactions.
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Affiliation(s)
| | - Jaiber J. Solano‐Iguaran
- Instituto de Ciencias Ambientales y EvolutivasUniversidad Austral de ChileValdiviaChile
- Departamento de Salud HidrobiológicaInstituto de Fomento PesqueroPuerto MonttChile
| | - Ana V. Longo
- Department of BiologyUniversity of FloridaGainesvilleFloridaUSA
| | - Juan D. Gaitán‐Espitia
- School of Biological Sciences and the SWIRE Institute of Marine ScienceThe University of Hong KongHong KongSARChina
| | | | - Mario Alvarado‐Rybak
- Núcleo de Ciencias Aplicadas en Ciencias Veterinarias y AgronómicasUniversidad de Las AméricasSantiagoChile
| | - Claudio Azat
- Sustainability Research Centre & PhD in Conservation MedicineUniversidad Andres BelloSantiagoChile
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Mossel P, Arif WM, De Souza GS, Varela LG, van der Weijden CWJ, Boersma HH, Willemsen ATM, Boellaard R, Elsinga PH, Borra RJH, Dierckx RAJO, Lammertsma AA, Bartels AL, Luurtsema G. Quantification of P-glycoprotein function at the human blood-brain barrier using [ 18F]MC225 and PET. Eur J Nucl Med Mol Imaging 2023; 50:3917-3927. [PMID: 37552369 PMCID: PMC10611838 DOI: 10.1007/s00259-023-06363-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023]
Abstract
INTRODUCTION P-glycoprotein (P-gp) is one of the most studied efflux transporters at the blood-brain barrier. It plays an important role in brain homeostasis by protecting the brain from a variety of endogenous and exogeneous substances. Changes in P-gp function are associated both with the onset of neuropsychiatric diseases, including Alzheimer's disease and Parkinson's disease, and with drug-resistance, for example in treatment-resistant depression. The most widely used approach to measure P-gp function in vivo is (R)-[11C]verapamil PET. (R)-[11C]verapamil is, however, an avid P-gp substrate, which complicates the use of this tracer to measure an increase in P-gp function as its baseline uptake is already very low. [18F]MC225 was developed to measure both increases and decreases in P-gp function. AIM The aim of this study was (1) to identify the pharmacokinetic model that best describes [18F]MC225 kinetics in the human brain and (2) to determine test-retest variability. METHODS Five (2 male, 3 female) of fourteen healthy subjects (8 male, 6 female, age 67 ± 5 years) were scanned twice (injected dose 201 ± 47 MBq) with a minimum interval of 2 weeks between scans. Each scanning session consisted of a 60-min dynamic [18F]MC225 scan with continuous arterial sampling. Whole brain grey matter data were fitted to a single tissue compartment model, and to reversible and irreversible two tissue-compartment models to obtain various outcome parameters (in particular the volume of distribution (VT), Ki, and the rate constants K1 and k2). In addition, a reversible two-tissue compartment model with fixed k3/k4 was included. The preferred model was selected based on the weighted Akaike Information Criterion (AIC) score. Test-retest variability (TRTV) was determined to assess reproducibility. RESULTS Sixty minutes post-injection, the parent fraction was 63.8 ± 4.0%. The reversible two tissue compartment model corrected for plasma metabolites with an estimated blood volume (VB) showed the highest AIC weight score of 34.3 ± 17.6%. The TRVT of the VT for [18F]MC225 PET scans was 28.3 ± 20.4% for the whole brain grey matter region using this preferred model. CONCLUSION [18F]MC225 VT, derived using a reversible two-tissue compartment model, is the preferred parameter to describe P-gp function in the human BBB. This outcome parameter has an average test-retest variability of 28%. TRIAL REGISTRATION EudraCT 2020-001564-28 . Registered 25 May 2020.
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Affiliation(s)
- Pascalle Mossel
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Wejdan M Arif
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- College of Applied Medical Science, Department of Radiological Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Giordana Salvi De Souza
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Lara Garcia Varela
- Molecular Imaging Biomarkers Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela (USC), 15706, Santiago de Compostela, Spain
- Nuclear Medicine Department and Molecular Imaging Group, Health Research Institute of Santiago de Compostela (IDIS), SERGAS, 15706, Santiago de Compostela, Spain
| | - Chris W J van der Weijden
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hendrikus H Boersma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Antoon T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ronald Boellaard
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiology and Nuclear Medicine, UMC, Location VUmc, Amsterdam, The Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ronald J H Borra
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Adriaan A Lammertsma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Anna L Bartels
- Department of Neurology, Ommelander Ziekenhuis Groep, Scheemda, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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Gauna F, Verger P, Fressard L, Jardin M, Ward JK, Peretti-Watel P. Vaccine hesitancy about the HPV vaccine among French young women and their parents: a telephone survey. BMC Public Health 2023; 23:628. [PMID: 37005583 PMCID: PMC10066945 DOI: 10.1186/s12889-023-15334-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 02/28/2023] [Indexed: 04/04/2023] Open
Abstract
BACKGROUND The human papillomavirus (HPV) vaccine reduces the burden of cervical and other cancers. In numerous countries, a slow uptakeof this vaccine persists, calling for a better understanding of the structural factors leading to vaccine acceptation. We aimed to assess the attitudes toward HPV vaccination among its intended public to explore its specific characteristics. METHODS A random cross-sectional telephone survey of the French general population provided data from a sample of 2426 respondents of the target public: the parents of young women and the young women aged 15-25 themselves. We applied cluster analysis to identify contrasting attitudinal profiles, and logistic regressions with a model averaging method to investigate and rank the factors associated with these profiles. RESULTS A third of the respondents had never heard of HPV. However, most of the respondents who had heard of it agreed that it is a severe (93.8%) and frequent (65.1%) infection. Overall, 72.3% of them considered the HPV vaccine to be effective, but 54% had concerns about its side effects. We identified four contrasting profiles based on their perceptions of this vaccine: informed supporters, objectors, uninformed supporters, and those who were uncertain. In multivariate analysis, these attitudinal clusters were the strongest predictors of HPV vaccine uptake, followed by attitudes toward vaccination in general. CONCLUSIONS Tailored information campaigns and programs should address the specific and contrasted concerns about HPV vaccination of both young women and of their parents.
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Affiliation(s)
- Fatima Gauna
- ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, Marseille, France.
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.
- IHU-Méditerranée Infection, Marseille, France.
| | - Pierre Verger
- ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, Marseille, France
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Lisa Fressard
- ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, Marseille, France
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Marie Jardin
- ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, Marseille, France
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
| | - Jeremy K Ward
- CERMES3 (INSERM, CNRS, EHESS, Université de Paris), Villejuif, France
| | - Patrick Peretti-Watel
- ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, Marseille, France
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
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Molina AN, Pulgar JM, Rezende EL, Carter MJ. Heat tolerance of marine ectotherms in a warming Antarctica. GLOBAL CHANGE BIOLOGY 2023; 29:179-188. [PMID: 36045500 DOI: 10.1111/gcb.16402] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Global warming is affecting the Antarctic continent in complex ways. Because Antarctic organisms are specialized to living in the cold, they are vulnerable to increasing temperatures, although quantitative analyses of this issue are currently lacking. Here we compiled a total of 184 estimates of heat tolerance belonging to 39 marine species and quantified how survival is affected concomitantly by the intensity and duration of thermal stress. Species exhibit thermal limits displaced toward colder temperatures, with contrasting strategies between arthropods and fish that exhibit low tolerance to acute heat challenges, and brachiopods, echinoderms, and molluscs that tend to be more sensitive to chronic exposure. These differences might be associated with mobility. A dynamic mortality model suggests that Antarctic organisms already encounter temperatures that might be physiologically stressful and indicate that these ecological communities are indeed vulnerable to ongoing rising temperatures.
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Affiliation(s)
- Andrés N Molina
- Departamento de Ecología, Facultad de Ciencias Biológicas, Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José M Pulgar
- Departamento de Ecología, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Enrico L Rezende
- Departamento de Ecología, Facultad de Ciencias Biológicas, Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mauricio J Carter
- Departamento de Ecología, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
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Verger P, Botelho-Nevers E, Garrison A, Gagnon D, Gagneur A, Gagneux-Brunon A, Dubé E. Vaccine hesitancy in health-care providers in Western countries: a narrative review. Expert Rev Vaccines 2022; 21:909-927. [PMID: 35315308 DOI: 10.1080/14760584.2022.2056026] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Vaccine hesitancy (VH) is a leading cause of suboptimal vaccine uptake rates worldwide. The interaction between patients and health-care providers (HCPs) is the keystone in addressing VH. However, significant proportions of HCPs, including those who administer vaccines, are personally and professionally vaccine-hesitant. AREAS COVERED This narrative review sought to characterize the nature, extent, correlates, and consequences of VH among HCPs. We included 39 quantitative and qualitative studies conducted in Western countries, published since 2015, that assessed VH among HCPs in general, for several vaccines. Studies were reviewed using the WHO 3Cs model - (lack of) confidence, complacency, and (lack of) convenience. EXPERT OPINION Despite the lack of validated tools and substantial heterogeneity in the methods used to measure VH among HCPs, this review confirms its presence in this population, at frequencies that vary by country, profession type, setting, and level of medical education. Lack of knowledge and mistrust in health authorities/pharmaceutical industry/experts were among its principal drivers. Improving the content about vaccination in HCPs' training programs, facilitating access to reliable information for use during consultations, and developing and validating instruments to measure HCPs' VH and its determinants are key to addressing VH among HCPs.
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Affiliation(s)
- Pierre Verger
- ORS Paca, Southeastern Health Regional Observatory, Marseille, France.,Faculty of Medicine, Aix-Marseille University, Marseille, France
| | - Elisabeth Botelho-Nevers
- Department of Infectious Diseases, University Hospital of Saint-Etienne, Saint-Etienne, France.,CIRI - Centre International de Recherche en Infectiologie, Lyon, France.,Univ Lyon, Jean Monnet University, Saint-Etienne, France.,Chair PreVacCi, Presage Institut, Jean Monnet University, Saint-Etienne, France
| | - Amanda Garrison
- ORS Paca, Southeastern Health Regional Observatory, Marseille, France.,Faculty of Medicine, Aix-Marseille University, Marseille, France
| | - Dominique Gagnon
- Direction des risques biologiques et de la santé au travail, Institut national de santé publique du Québec, Quebec, Canada
| | - Arnaud Gagneur
- Department of Pediatrics, Centre de Recherche du CHUS, Quebec, Canada.,Faculté de médecine et des sciences de la santé, Département de pédiatrie, Université de Sherbrooke-Campus de la Santé, Quebec, Canada
| | - Amandine Gagneux-Brunon
- Department of Infectious Diseases, University Hospital of Saint-Etienne, Saint-Etienne, France.,CIRI - Centre International de Recherche en Infectiologie, Lyon, France.,Univ Lyon, Jean Monnet University, Saint-Etienne, France.,Chair PreVacCi, Presage Institut, Jean Monnet University, Saint-Etienne, France.,CIC INSERM Vaccinology, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Eve Dubé
- Deptartment of Anthropology, Laval University, Quebec, Canada
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8
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Verger P, Peretti-Watel P, Gagneux-Brunon A, Botelho-Nevers E, Sanchez A, Gauna F, Fressard L, Bonneton M, Launay O, Ward JK. Acceptance of childhood and adolescent vaccination against COVID-19 in France: a national cross-sectional study in May 2021. Hum Vaccin Immunother 2021; 17:5082-5088. [PMID: 34905467 PMCID: PMC8904022 DOI: 10.1080/21645515.2021.2004838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The French health authorities extended vaccination against COVID-19 to adolescents in June 2021, during the epidemic resurgence linked to the delta variant and because of insufficient vaccination coverage to ensure collective protection. In May 2021, we conducted a national online cross-sectional survey of 2533 adults in France to study their attitudes toward COVID-19 vaccines and their acceptance of child/adolescent vaccination according to targeted age groups (<6 years; 6-11; 12-17) and its determinants. We applied a multi-model averaged logistic regression for each of these age groups to study the determinants of favorability to vaccination. Among the respondents, 62.7% (1597) accepted COVID-19 vaccination for adolescents, 48.3% (1223) for children aged 6-11 years, and only 31% (783) for children under 6 years. Acceptance increased with fear of contracting COVID-19 and trust in institutions and decreased as the COVID-19 vaccine risk perception score increased. People favorable to vaccination in general and those sensitive to social pressure were also more often favorable to vaccinating children/adolescents than those who were not. Drivers of acceptance were ranked differently for the different age groups. Understanding these differences is essential to anticipating obstacles to vaccination of these age groups and designing appropriate information and motivational strategies to support it.
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Affiliation(s)
- Pierre Verger
- Southeastern Health Regional Observatory (ORS PACA), Marseille, France,Inserm, F-CRIN, I-REIVAC/COVIREIVAC, Paris, France,CONTACT Pierre Verger Observatoire Régional de la Santé Paca, Faculté De Médecine, 27, Bd Jean Moulin, 13385Marseille, Cedex 5, France
| | - Patrick Peretti-Watel
- Southeastern Health Regional Observatory (ORS PACA), Marseille, France,VITROME (Aix Marseille Université, IRD, AP-HM, SSA), Marseille, France
| | - Amandine Gagneux-Brunon
- Inserm, F-CRIN, I-REIVAC/COVIREIVAC, Paris, France,Centre International De Recherche En Infectiologie, Team Gimap, Univ Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, Inserm, U1111, CNRS, Lyon, France,CIC Inserm 1408 Vaccinologie, Chu De Saint-Etienne, France,Chaire PREVACCI, Université Jean Monnet, Saint-Etienne, France
| | - Elisabeth Botelho-Nevers
- Centre International De Recherche En Infectiologie, Team Gimap, Univ Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, Inserm, U1111, CNRS, Lyon, France,CIC Inserm 1408 Vaccinologie, Chu De Saint-Etienne, France,Chaire PREVACCI, Université Jean Monnet, Saint-Etienne, France
| | - Alvaro Sanchez
- Assistance Publique – Hôpitaux De Paris, Hôpital Cochin, Paris, France
| | - Fatima Gauna
- Southeastern Health Regional Observatory (ORS PACA), Marseille, France
| | - Lisa Fressard
- Southeastern Health Regional Observatory (ORS PACA), Marseille, France
| | - Marion Bonneton
- Inserm, F-CRIN, I-REIVAC/COVIREIVAC, Paris, France,Université De Paris, Inserm CIC 1417, Assistance Publique – Hôpitaux De Paris, Hôpital Cochin, Paris, France
| | - Odile Launay
- Inserm, F-CRIN, I-REIVAC/COVIREIVAC, Paris, France,Université De Paris, Inserm CIC 1417, Assistance Publique – Hôpitaux De Paris, Hôpital Cochin, Paris, France
| | - Jeremy K. Ward
- VITROME (Aix Marseille Université, IRD, AP-HM, SSA), Marseille, France,CERMES3 (Inserm, CNRS, Ehess, Université De Paris), Villejuif, France
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9
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Using Isotopic Data to Evaluate Esox lucius (Linnaeus, 1758) Natal Origins in a Hydrologically Complex River Basin. FISHES 2021. [DOI: 10.3390/fishes6040067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Otolith microchemistry has emerged as a powerful technique with which to identify the natal origins of fishes, but it relies on differences in underlying geology that may occur over large spatial scales. An examination of how small a spatial scale on which this technique can be implemented, especially in water bodies that share a large proportion of their flow, would be useful for guiding aquatic invasive species control efforts. We examined trace isotopic signatures in northern pike (Esox lucius) otoliths to estimate their provenance between two reservoirs in the Upper Yampa River Basin, Colorado, USA. This is a challenging study area as these reservoirs are only 11-rkm apart on the same river and thus share a high proportion of their inflow. We found that three isotopes (86Sr, 137Ba, and 55Mn) were useful in discriminating between these reservoirs, but their signatures varied annually, and the values overlapped. Strontium isotope ratios (87Sr/86Sr) were different between sites and relatively stable across three years, which made them an ideal marker for determining northern pike provenance. Our study demonstrates the usefulness of otolith microchemistry for natal origin determination within the same river over a relatively small spatial scale when there are geologic differences between sites, especially geologic differences underlying tributaries between sites.
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D'Alonzo RA, Gill S, Rowshanfarzad P, Keam S, MacKinnon KM, Cook AM, Ebert MA. In vivo noninvasive preclinical tumor hypoxia imaging methods: a review. Int J Radiat Biol 2021; 97:593-631. [PMID: 33703994 DOI: 10.1080/09553002.2021.1900943] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/28/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022]
Abstract
Tumors exhibit areas of decreased oxygenation due to malformed blood vessels. This low oxygen concentration decreases the effectiveness of radiation therapy, and the resulting poor perfusion can prevent drugs from reaching areas of the tumor. Tumor hypoxia is associated with poorer prognosis and disease progression, and is therefore of interest to preclinical researchers. Although there are multiple different ways to measure tumor hypoxia and related factors, there is no standard for quantifying spatial and temporal tumor hypoxia distributions in preclinical research or in the clinic. This review compares imaging methods utilized for the purpose of assessing spatio-temporal patterns of hypoxia in the preclinical setting. Imaging methods provide varying levels of spatial and temporal resolution regarding different aspects of hypoxia, and with varying advantages and disadvantages. The choice of modality requires consideration of the specific experimental model, the nature of the required characterization and the availability of complementary modalities as well as immunohistochemistry.
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Affiliation(s)
- Rebecca A D'Alonzo
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Suki Gill
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Synat Keam
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Kelly M MacKinnon
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Alistair M Cook
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Martin A Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
- 5D Clinics, Claremont, Australia
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Cubas J, Kluge J, Bello-Rodríguez V, del Arco MJ, Cooke B, González-Mancebo JM. Can habitat type predict the abundance of the European rabbits on oceanic islands? COMMUNITY ECOL 2021. [DOI: 10.1007/s42974-021-00039-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Tiepolt S, Becker GA, Wilke S, Cecchin D, Rullmann M, Meyer PM, Barthel H, Hesse S, Patt M, Luthardt J, Wagenknecht G, Sattler B, Deuther-Conrad W, Ludwig FA, Fischer S, Gertz HJ, Smits R, Hoepping A, Steinbach J, Brust P, Sabri O. (+)-[ 18F]Flubatine as a novel α4β2 nicotinic acetylcholine receptor PET ligand-results of the first-in-human brain imaging application in patients with β-amyloid PET-confirmed Alzheimer's disease and healthy controls. Eur J Nucl Med Mol Imaging 2021; 48:731-746. [PMID: 32935187 PMCID: PMC8036219 DOI: 10.1007/s00259-020-05029-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/07/2020] [Indexed: 11/25/2022]
Abstract
PURPOSES We present the first in-human brain PET imaging data of the new α4β2 nicotinic acetylcholine receptor (nAChR)-targeting radioligand (+)-[18F]Flubatine. Aims were to develop a kinetic modeling-based approach to quantify (+)-[18F]Flubatine and compare the data of healthy controls (HCs) and patients with Alzheimer's disease (AD); to investigate the partial volume effect (PVE) on regional (+)-[18F]Flubatine binding; and whether (+)-[18F]Flubatine binding and cognitive test data respective β-amyloid radiotracer accumulation were correlated. METHODS We examined 11 HCs and 9 mild AD patients. All subjects underwent neuropsychological testing and [11C]PiB PET/MRI examination. (+)-[18F]Flubatine PET data were evaluated using full kinetic modeling and regional as well as voxel-based analyses. RESULTS With 270-min p.i., the unchanged parent compound amounted to 97 ± 2%. Adequate fits of the time-activity curves were obtained with the 1 tissue compartment model (1TCM). (+)-[18F]Flubatine distribution volume (binding) was significantly reduced in bilateral mesial temporal cortex in AD patients compared with HCs (right 10.6 ± 1.1 vs 11.6 ± 1.4, p = 0.049; left 11.0 ± 1.1 vs 12.2 ± 1.8, p = 0.046; one-sided t tests each). PVE correction increased not only (+)-[18F]Flubatine binding of approximately 15% but also standard deviation of 0.4-70%. Cognitive test data and (+)-[18F]Flubatine binding were significantly correlated in the left anterior cingulate, right posterior cingulate, and right parietal cortex (r > 0.5, p < 0.05 each). In AD patients, (+)-[18F]Flubatine binding and [11C]PiB standardized uptake value ratios were negatively correlated in several regions; whereas in HCs, a positive correlation between cortical (+)-[18F]Flubatine binding and [11C]PiB accumulation in the white matter was found. No adverse event related to (+)-[18F]Flubatine occurred. CONCLUSION (+)-[18F]Flubatine is a safe and stable PET ligand. Full kinetic modeling can be realized by 1TCM without metabolite correction. (+)-[18F]Flubatine binding affinity was high enough to detect group differences. Of interest, correlation between white matter β-amyloid PET uptake and (+)-[18F]Flubatine binding indicated an association between white matter integrity and availability of α4β2 nAChRs. Overall, (+)-[18F]Flubatine showed favorable characteristics and has therefore the potential to serve as α4β2 nAChR-targeting PET ligand in further clinical trials.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Georg-Alexander Becker
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Stephan Wilke
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Diego Cecchin
- Department of Medicine, University-Hospital of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Philipp M. Meyer
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Julia Luthardt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Gudrun Wagenknecht
- Electronic Systems (ZEA-2), Central Institute for Engineering, Electronics and Analytics, Research Centre Juelich, Wilhelm-Johnen-Straße, 52428 Juelich, Germany
| | - Bernhard Sattler
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | | | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Hermann-Josef Gertz
- Department of Psychiatry, University of Leipzig, Semmelweisstraße 10, 04103 Leipzig, Germany
| | - René Smits
- ABX advanced biochemical compounds GmbH, Heinrich-Gläser-Straße 10, 01454 Radeberg, Germany
| | - Alexander Hoepping
- ABX advanced biochemical compounds GmbH, Heinrich-Gläser-Straße 10, 01454 Radeberg, Germany
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzener Landstr. 400, 01328 Dresden, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
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Verger P, Scronias D, Dauby N, Adedzi KA, Gobert C, Bergeat M, Gagneur A, Dubé E. Attitudes of healthcare workers towards COVID-19 vaccination: a survey in France and French-speaking parts of Belgium and Canada, 2020. ACTA ACUST UNITED AC 2021; 26. [PMID: 33478623 PMCID: PMC7848677 DOI: 10.2807/1560-7917.es.2021.26.3.2002047] [Citation(s) in RCA: 235] [Impact Index Per Article: 78.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In October and November 2020, we conducted a survey of 2,678 healthcare workers (HCWs) involved in general population immunisation in France, French-speaking Belgium and Quebec, Canada to assess acceptance of future COVID-19 vaccines (i.e. willingness to receive or recommend these) and its determinants. Of the HCWs, 48.6% (n = 1,302) showed high acceptance, 23.0% (n = 616) moderate acceptance and 28.4% (n = 760) hesitancy/reluctance. Hesitancy was mostly driven by vaccine safety concerns. These must be addressed before/during upcoming vaccination campaigns.
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Affiliation(s)
- Pierre Verger
- ORS PACA (Southeastern Health Regional Observatory), Faculty of Medicine, Marseille, France
| | - Dimitri Scronias
- Centre d'investigation clinique de l'Hôpital Cochin-Pasteur (CIC 1417), Assistance Publique des Hôpitaux de Paris, Paris, France.,ORS PACA (Southeastern Health Regional Observatory), Faculty of Medicine, Marseille, France
| | - Nicolas Dauby
- Institute for Medical Immunology, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Centre for Environmental Health and Occupational Health, School of Public Health, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Department of Infectious Diseases, CHU Saint-Pierre - Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Kodzo Awoenam Adedzi
- Centre de recherche du CHU de Québec - Université Laval, D'Estimauville, Quebec City, Canada
| | - Cathy Gobert
- General Practice, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Maxime Bergeat
- Maxime Bergeat (MS) - French Ministry for Solidarity and Health - Statistical Service (DREES), Paris, France
| | - Arnaud Gagneur
- Université de Sherbrooke-campus de la santé, Sherbrooke, Quebec, Canada.,Department of Pediatrics, centre de recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Eve Dubé
- Anthropology Department, Laval University, Quebec City, Canada.,Centre de recherche du CHU de Québec - Université Laval, D'Estimauville, Quebec City, Canada
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Dubash S, Inglese M, Mauri F, Kozlowski K, Trivedi P, Arshad M, Challapalli A, Barwick T, Al-Nahhas A, Stanbridge R, Lewanski C, Berry M, Bowen F, Aboagye EO. Spatial heterogeneity of radiolabeled choline positron emission tomography in tumors of patients with non-small cell lung cancer: first-in-patient evaluation of [ 18F]fluoromethyl-(1,2- 2H 4)-choline. Theranostics 2020; 10:8677-8690. [PMID: 32754271 PMCID: PMC7392021 DOI: 10.7150/thno.47298] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/19/2020] [Indexed: 12/26/2022] Open
Abstract
Purpose: The spatio-molecular distribution of choline and its metabolites in tumors is highly heterogeneous. Due to regulation of choline metabolism by hypoxic transcriptional signaling and other survival factors, we envisage that detection of such heterogeneity in patient tumors could provide the basis for advanced localized therapy. However, non-invasive methods to assess this phenomenon in patients are limited. We investigated such heterogeneity in Non-Small Cell Lung Cancer (NSCLC) with [18F]fluoromethyl-(1,2-2H4) choline ([18F]D4-FCH) and positron emission tomography/computed tomography (PET/CT). Experimental design: [18F]D4-FCH (300.5±72.9MBq [147.60-363.6MBq]) was administered intravenously to 17 newly diagnosed NSCLC patients. PET/CT scans were acquired concurrently with radioactive blood sampling to permit mathematical modelling of blood-tissue transcellular rate constants. Comparisons were made with biopsy-derived choline kinase-α (CHKα) expression and diagnostic [18F]fluorodeoxyglucose ([18F]FDG) scans. Results: Oxidation of [18F]D4-FCH to [18F]D4-fluorobetaine was suppressed (48.58±0.31% parent at 60 min) likely due to the deuterium isotope effect embodied within the design of the radiotracer. Early (5 min) and late (60 min) images showed specific uptake of tracer in all 51 lesions (tumors, lymph nodes and metastases) from 17 patients analyzed. [18F]D4-FCH-derived uptake (SUV60max) in index primary lesions (n=17) ranged between 2.87-10.13; lower than that of [18F]FDG PET [6.89-22.64]. Mathematical modelling demonstrated net irreversible uptake of [18F]D4-FCH at steady-state, and parametric mapping of the entire tumor showed large intratumorally heterogeneity in radiotracer retention, which is likely to have influenced correlations with biopsy-derived CHKα expression. Conclusions: [18F]D4-FCH is detectable in NSCLC with large intratumorally heterogeneity, which could be exploited in the future for targeting localized therapy.
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Affiliation(s)
- Suraiya Dubash
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Marianna Inglese
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Francesco Mauri
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Kasia Kozlowski
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Pritesh Trivedi
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Mubarik Arshad
- Department of Surgery and Cancer, Imperial College London, United Kingdom
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | | | - Tara Barwick
- Department of Surgery and Cancer, Imperial College London, United Kingdom
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Adil Al-Nahhas
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Rex Stanbridge
- Department of Surgery and Cancer, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Conrad Lewanski
- Department of Surgery and Cancer, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Matthew Berry
- Department of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Frances Bowen
- Department of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Eric O. Aboagye
- Department of Surgery and Cancer, Imperial College London, United Kingdom
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15
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Kero T, Sörensen J, Antoni G, Wilking H, Carlson K, Vedin O, Rosengren S, Wikström G, Lubberink M. Quantification of 11C-PIB kinetics in cardiac amyloidosis. J Nucl Cardiol 2020; 27:774-784. [PMID: 30039218 PMCID: PMC7326793 DOI: 10.1007/s12350-018-1349-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/23/2018] [Indexed: 01/15/2023]
Abstract
BACKGROUND The purpose of this work was to determine the optimal tracer kinetic model of 11C-PIB and to validate the use of the simplified methods retention index (RI) and standardized uptake value (SUV) for quantification of cardiac 11C-PIB uptake in amyloidosis. METHODS AND RESULTS Single-tissue, reversible and irreversible two-tissue models were fitted to data from seven cardiac amyloidosis patients who underwent 11C-PIB PET scans and arterial blood sampling for measurement of blood radioactivity and metabolites. The irreversible two-tissue model (2Tirr) best described cardiac 11C-PIB uptake. RI and SUV showed high correlation with the rate of irreversible binding (Ki) from the 2Tirr model (r2 =0.95 and r2 =0.94). Retrospective data from 10 amyloidosis patients and 5 healthy controls were analyzed using RI, SUV, as well as compartment modelling with a population-average metabolite correction. All measures were higher in amyloidosis patients than in healthy controls (p=.001), but with an overlap between groups for Ki. CONCLUSION An irreversible two-tissue model best describes the 11C-PIB uptake in cardiac amyloidosis. RI and SUV correlate well with Ki from the 2Tirr model. RI and SUV discriminate better between amyloidosis patients and controls than Ki based on population-average metabolite correction.
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Affiliation(s)
- Tanja Kero
- Department of Surgical Science, Uppsala University, Uppsala, Sweden.
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden.
- PET Center/Medical Imaging Center, Uppsala University Hospital, 75185, Uppsala, Sweden.
| | - Jens Sörensen
- Department of Surgical Science, Uppsala University, Uppsala, Sweden
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Gunnar Antoni
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Helena Wilking
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Kristina Carlson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Department of Hematology, Uppsala University Hospital, Uppsala, Sweden
| | - Ola Vedin
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Department of Cardiology, Uppsala University Hospital, Uppsala, Sweden
| | - Sara Rosengren
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Department of Hematology, Uppsala University Hospital, Uppsala, Sweden
| | - Gerhard Wikström
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Department of Cardiology, Uppsala University Hospital, Uppsala, Sweden
| | - Mark Lubberink
- Department of Surgical Science, Uppsala University, Uppsala, Sweden
- Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden
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Dikaios N. Stochastic Gradient Langevin dynamics for joint parameterization of tracer kinetic models, input functions, and T1 relaxation-times from undersampled k-space DCE-MRI. Med Image Anal 2020; 62:101690. [DOI: 10.1016/j.media.2020.101690] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/16/2020] [Accepted: 03/13/2020] [Indexed: 02/04/2023]
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17
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Robust nonlinear parameter estimation in tracer kinetic analysis using infinity norm regularization and particle swarm optimization. Phys Med 2020; 72:60-72. [PMID: 32200299 DOI: 10.1016/j.ejmp.2020.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 11/23/2022] Open
Abstract
In positron emission tomography (PET) studies, the voxel-wise calculation of individual rate constants describing the tracer kinetics is quite challenging because of the nonlinear relationship between the rate constants and PET data and the high noise level in voxel data. Based on preliminary simulations using a standard two-tissue compartment model, we can hypothesize that it is possible to reduce errors in the rate constant estimates when constraining the overestimation of the larger of two exponents in the model equation. We thus propose a novel approach based on infinity-norm regularization for limiting this exponent. Owing to the non-smooth cost function of this regularization scheme, which prevents the use of conventional Jacobian-based optimization methods, we examined a proximal gradient algorithm and the particle swarm optimization (PSO) through a simulation study. Because it exploits multiple initial values, the PSO method shows much better convergence than the proximal gradient algorithm, which is susceptible to the initial values. In the implementation of PSO, the use of a Gamma distribution to govern random movements was shown to improve the convergence rate and stability compared to a uniform distribution. Consequently, Gamma-based PSO with regularization was shown to outperform all other methods tested, including the conventional basis function method and Levenberg-Marquardt algorithm, in terms of its statistical properties.
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Christodoulou D, Kuehne A, Estermann A, Fuhrer T, Lang P, Sauer U. Reserve Flux Capacity in the Pentose Phosphate Pathway by NADPH Binding Is Conserved across Kingdoms. iScience 2019; 19:1133-1144. [PMID: 31536961 PMCID: PMC6831883 DOI: 10.1016/j.isci.2019.08.047] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 07/13/2019] [Accepted: 08/24/2019] [Indexed: 02/03/2023] Open
Abstract
All organisms evolved defense mechanisms to counteract oxidative stress and buildup of reactive oxygen species (ROS). To test whether a potentially conserved mechanism exists for the rapid response, we investigated immediate metabolic dynamics of Escherichia coli, yeast, and human dermal fibroblasts to oxidative stress that we found to be conserved between species. To elucidate the regulatory mechanisms that implement this metabolic response, we developed mechanistic kinetic models for each organism's central metabolism and systematically tested activation and inactivation of each irreversible reaction by each metabolite. This ensemble modeling predicts in vivo relevant metabolite-enzyme interactions based on their ability to quantitatively describe metabolite dynamics. All three species appear to inhibit their oxidative pentose phosphate pathway during normal growth by the redox cofactor NADPH and relieve this inhibition to increase the pathway flux for detoxification of ROS during stress, with the sole exception of yeast when exposed to high levels of stress.
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Affiliation(s)
- Dimitris Christodoulou
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland; Systems Biology Graduate School, Zurich 8057, Switzerland
| | - Andreas Kuehne
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland; Systems Biology Graduate School, Zurich 8057, Switzerland
| | | | - Tobias Fuhrer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Paul Lang
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
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Pitman KE, Alluri SR, Kristian A, Aarnes EK, Lyng H, Riss PJ, Malinen E. Influx rate of 18F-fluoroaminosuberic acid reflects cystine/glutamate antiporter expression in tumour xenografts. Eur J Nucl Med Mol Imaging 2019; 46:2190-2198. [PMID: 31264167 DOI: 10.1007/s00259-019-04375-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/27/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE 18F-fluoroaminosuberic acid (18F-FASu) is a recently developed amino acid tracer for positron emission tomography (PET) of oxidative stress that may offer improved tumour assessment over the conventional tracer 18F-fluorodeoxyglucose (18F-FDG). Our aim was to evaluate and relate dynamic 18F-FASu and 18F-FDG uptake with pharmacokinetic modelling to transporter protein expression levels in a panel of diverse tumour xenograft lines. METHODS Four different tumour xenograft lines were implanted in female athymic nude mice: MAS98.12 and HBCx3 (breast), TPMX (osteosarcoma) and A549 (lung). Dynamic PET over 60 min was performed on a small animal unit. The time-activity curves (TACs) for 18F-FASu and 18F-FDG in individual tumours were used to extract early (SUVE; 2 min p.i.) and late (SUVL; 55 min p.i.) standardised uptake values. Pharmacokinetic two-tissue compartment models were applied to the TACs to estimate rate constants K1-k4 and blood volume fraction vB. Relative levels of cystine/glutamate antiporter subunit xCT were assessed by western blotting, and expression of GLUT1 and CD31 by immunohistochemistry. RESULTS 18F-FASu showed higher SUVE, whilst 18F-FDG exhibited higher SUVL. Influx rate K1 for 18F-FASu was significantly correlated with xCT levels (p = 0.001) and was significantly higher than K1 for 18F-FDG (p < 0.001). K1 for 18F-FDG was significantly correlated with GLUT1 levels (p = 0.002). vB estimated from 18F-FASu and 18F-FDG TACs was highly consistent and significantly correlated (r = 0.85, p < 0.001). Two qualitatively different 18F-FASu uptake profiles were identified: type α with low xCT expression and low K1 (A549 and HBCx3), and type β with high xCT expression and high K1 (MAS98.12 and TPMX). CONCLUSION The influx rate of 18F-FASu reflects xCT activity in tumour xenografts. Dynamic PET with pharmacokinetic modelling is needed to fully appraise 18F-FASu distribution routes.
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Affiliation(s)
- Kathinka E Pitman
- Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway
- Department of Medical Physics, Oslo University Hospital, Oslo, Norway
| | - Santosh R Alluri
- Department of Chemistry, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway
| | | | | | - Heidi Lyng
- Department of Radiation Biology, Oslo University Hospital, Oslo, Norway
| | - Patrick J Riss
- Department of Chemistry, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway
| | - Eirik Malinen
- Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway.
- Department of Medical Physics, Oslo University Hospital, Oslo, Norway.
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Fiorentino M, Protière C, Sagaon-Teyssier L, Mimi M, Fressard L, Arnold M, Lambotte O, Barbot J, Fainzang S, Meyer L, Goujard C, Préau M, Spire B, Suzan-Monti M. What is the effect of self-identified HIV activism in willingness to participate in HIV cure-related clinical trials? Results from the ANRS-APSEC study. J Virus Erad 2019. [DOI: 10.1016/s2055-6640(20)30045-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Effects of Land Cover Pattern Along Urban-Rural Gradient on Bird Diversity in Wetlands. DIVERSITY 2019. [DOI: 10.3390/d11060086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Wetlands play an important role in the feeding, breeding, and lives of birds. However, available habitats for bird species are changing due to intensifying human activity, especially in the context of China’s mass urbanization. Urban sprawl has taken over the wetlands along the lakes in the past decades, which places tremendous pressure on wetland ecosystems and, therefore, on bird communities. However, the ways urban land cover pattern along the urban-rural gradient affects bird communities is still unclear. To investigate the influence of land cover pattern on the α and β diversity of birds in the urban-rural gradient we chose 31 sites distributed within the wetlands around the Dianchi Lake in Yunnan, China. We calculated the species richness to indicate α diversity and used the Morisita–Horn index to indicate β diversity. Meanwhile, we assessed the land cover pattern of each site by measuring the proportion of emergent plants, floating plants, submerged plants, ponds, forests, lawns, roads, agricultural lands and built lands in a quadrat of 1 square kilometer. Simple linear regressions, model selection, and an averaging approach based on corrected Akaike information criterion (AICc) were used to test the effects of land cover pattern on bird diversity. Using one-way ANOVA and Tukey’s HSD (honestly significant difference) test, we compared the difference between α and β diversity, respectively, along the urban-rural gradient. Based on our analyses, urban and suburban wetland birds were significantly homogeneous. The community structure in rural wetlands, however, was significantly different from that of the suburban and urban areas. According to our research, the land cover patterns that influenced bird species richness were the built lands acreage, submerged plants acreage, ponds acreage, and the edge density of emergent plants. Meanwhile, of these variables, the built lands acreage, ponds acreage and edge density of emergent plants were significantly different in urban, suburban, and rural wetlands. Therefore, to maintain high biodiversity in wetlands affected by urbanization, we must pay more attention to the land cover patterns.
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Wilson R, Scronias D, Zaytseva A, Ferry MA, Chamboredon P, Dubé E, Verger P. Seasonal influenza self-vaccination behaviours and attitudes among nurses in Southeastern France. Hum Vaccin Immunother 2019; 15:2423-2433. [PMID: 30829102 DOI: 10.1080/21645515.2019.1587274] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Despite seasonal influenza vaccination (SIV) being recommended to healthcare professionals to protect themselves and their patients, uptake is low, especially among nurses. We sought to study self-vaccination behaviours, attitudes and knowledge about SIV among nurses in Southeastern France. METHODS A cross-sectional survey with community and hospital-based hospital nurses was conducted with the same standardised questionnaire. Multi-model averaging approaches studied factors associated with the following dependent variables: self-reported SIV uptake; and considering SIV a professional responsibility. RESULTS 1539 nurses completed the questionnaire (response rate: 85%). SIV was the most frequently cited vaccine (49%) regarding nurses' unfavourable opinions towards specific vaccines. Thirty-four percent of nurses reported being vaccinated at least once during the 2015-2016 or 2016-2017 seasons. A lack of perceived personal vulnerability to influenza, a fear of adverse effects, and a preference for homeopathy constituted the main deterrents of SIV. Nurses held various misconceptions about the SIV, but 69% considered its benefits to be greater than its risks. The multi-model averaging approach showed that considering SIV as a professional responsibility was the main factor associated with SIV uptake among nurses (Nagelkerke's partial R-squared: 15%). This sense of responsibility was strongly associated with trust in various vaccine information sources. CONCLUSION Nurses had low SIV uptake rates and held various concerns and a lack of knowledge surrounding the vaccine. This is concerning considering the impact that these factors can have on nurses and patients' health, especially considering the increased role that nurses could have surrounding SIV in the near future.
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Affiliation(s)
- Rose Wilson
- ORS PACA, Southeastern Health Regional Observatory , Marseille , France.,IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Aix Marseille Univ , Marseille , France
| | - Dimitri Scronias
- IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Aix Marseille Univ , Marseille , France
| | - Anna Zaytseva
- ORS PACA, Southeastern Health Regional Observatory , Marseille , France.,IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Aix Marseille Univ , Marseille , France
| | - Marie-Ange Ferry
- Conseil Inter-Régional de l'Ordre des Infirmiers (CIROI) PACA , Corse , France
| | - Patrick Chamboredon
- Conseil Inter-Régional de l'Ordre des Infirmiers (CIROI) PACA , Corse , France
| | - Eve Dubé
- Department of Social and Preventive Medicine, Institut National de Santé publique du Québec , Québec , Canada
| | - Pierre Verger
- ORS PACA, Southeastern Health Regional Observatory , Marseille , France.,IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Aix Marseille Univ , Marseille , France
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23
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Zeng J, Fletcher D, Dillingham PW, Cornwall CE. Studentized bootstrap model-averaged tail area intervals. PLoS One 2019; 14:e0213715. [PMID: 30883568 PMCID: PMC6422275 DOI: 10.1371/journal.pone.0213715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/27/2019] [Indexed: 11/24/2022] Open
Abstract
In many scientific studies, the underlying data-generating process is unknown and multiple statistical models are considered to describe it. For example, in a factorial experiment we might consider models involving just main effects, as well as those that include interactions. Model-averaging is a commonly-used statistical technique to allow for model uncertainty in parameter estimation. In the frequentist setting, the model-averaged estimate of a parameter is a weighted mean of the estimates from the individual models, with the weights typically being based on an information criterion, cross-validation, or bootstrapping. One approach to building a model-averaged confidence interval is to use a Wald interval, based on the model-averaged estimate and its standard error. This has been the default method in many application areas, particularly those in the life sciences. The MA-Wald interval, however, assumes that the studentized model-averaged estimate has a normal distribution, which can be far from true in practice due to the random, data-driven model weights. Recently, the model-averaged tail area Wald interval (MATA-Wald) has been proposed as an alternative to the MA-Wald interval, which only assumes that the studentized estimate from each model has a N(0, 1) or t-distribution, when that model is true. This alternative to the MA-Wald interval has been shown to have better coverage in simulation studies. However, when we have a response variable that is skewed, even these relaxed assumptions may not be valid, and use of these intervals might therefore result in poor coverage. We propose a new interval (MATA-SBoot) which uses a parametric bootstrap approach to estimate the distribution of the studentized estimate for each model, when that model is true. This method only requires that the studentized estimate from each model is approximately pivotal, an assumption that will often be true in practice, even for skewed data. We illustrate use of this new interval in the analysis of a three-factor marine global change experiment in which the response variable is assumed to have a lognormal distribution. We also perform a simulation study, based on the example, to compare the lower and upper error rates of this interval with those for existing methods. The results suggest that the MATA-SBoot interval can provide better error rates than existing intervals when we have skewed data, particularly for the upper error rate when the sample size is small.
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Affiliation(s)
- Jiaxu Zeng
- Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
- * E-mail:
| | - David Fletcher
- Department of Mathematics and Statistics, University of Otago, Dunedin, New Zealand
| | - Peter W. Dillingham
- Department of Mathematics and Statistics, University of Otago, Dunedin, New Zealand
- School of Science and Technology, University of New England, Armidale, Australia
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24
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Gould AL. BMA‐Mod: A Bayesian model averaging strategy for determining dose‐response relationships in the presence of model uncertainty. Biom J 2018; 61:1141-1159. [DOI: 10.1002/bimj.201700211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 08/30/2018] [Accepted: 11/14/2018] [Indexed: 12/24/2022]
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25
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Buffing MF, Link H, Christodoulou D, Sauer U. Capacity for instantaneous catabolism of preferred and non-preferred carbon sources in Escherichia coli and Bacillus subtilis. Sci Rep 2018; 8:11760. [PMID: 30082753 PMCID: PMC6079084 DOI: 10.1038/s41598-018-30266-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/26/2018] [Indexed: 02/08/2023] Open
Abstract
Making the right choice for nutrient consumption in an ever-changing environment is a key factor for evolutionary success of bacteria. Here we investigate the regulatory mechanisms that enable dynamic adaptation between non-preferred and preferred carbon sources for the model Gram-negative and -positive species Escherichia coli and Bacillus subtilis, respectively. We focus on the ability for instantaneous catabolism of a gluconeogenic carbon source upon growth on a glycolytic carbon source and vice versa. By following isotopic tracer dynamics on a 1–2 minute scale, we show that flux reversal from the preferred glucose to non-preferred pyruvate as the sole carbon source is primarily transcriptionally regulated. In the opposite direction, however, E. coli can reverse its flux instantaneously by means of allosteric regulation, whereas in B. subtilis this flux reversal is transcriptionally regulated. Upon removal of transcriptional regulation, B. subtilis assumes the ability of instantaneous glucose catabolism. Using an approach that combines quantitative metabolomics and kinetic modelling, we then identify the additionally necessary key metabolite-enzyme interactions that implement the instantaneous flux reversal in the transcriptionally deregulated B. subtilis, and validate the most relevant allosteric interactions.
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Affiliation(s)
- Marieke F Buffing
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Hannes Link
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Dimitris Christodoulou
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
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26
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Reserve Flux Capacity in the Pentose Phosphate Pathway Enables Escherichia coli's Rapid Response to Oxidative Stress. Cell Syst 2018; 6:569-578.e7. [PMID: 29753645 DOI: 10.1016/j.cels.2018.04.009] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 01/19/2018] [Accepted: 04/10/2018] [Indexed: 01/01/2023]
Abstract
To counteract oxidative stress and reactive oxygen species (ROS), bacteria evolved various mechanisms, primarily reducing ROS through antioxidant systems that utilize cofactor NADPH. Cells must stabilize NADPH levels by increasing flux through replenishing metabolic pathways like pentose phosphate (PP) pathway. Here, we investigate the mechanism enabling the rapid increase in NADPH supply by exposing Escherichia coli to hydrogen peroxide and quantifying the immediate metabolite dynamics. To systematically infer active regulatory interactions governing this response, we evaluated ensembles of kinetic models of glycolysis and PP pathway, each with different regulation mechanisms. Besides the known inactivation of glyceraldehyde 3-phosphate dehydrogenase by ROS, we reveal the important allosteric inhibition of the first PP pathway enzyme by NADPH. This NADPH feedback inhibition maintains a below maximum-capacity PP pathway flux under non-stress conditions. Relieving this inhibition instantly increases PP pathway flux upon oxidative stress. We demonstrate that reducing cells' capacity to rapidly reroute their flux through the PP pathway increases their oxidative stress sensitivity.
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27
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Wang B, Nishikawa K, Matsui M, Nguyen TQ, Xie F, Li C, Khatiwada JR, Zhang B, Gong D, Mo Y, Wei G, Chen X, Shen Y, Yang D, Xiong R, Jiang J. Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts. PeerJ 2018; 6:e4384. [PMID: 29576937 PMCID: PMC5853667 DOI: 10.7717/peerj.4384] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/29/2018] [Indexed: 11/20/2022] Open
Abstract
Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations.
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Affiliation(s)
- Bin Wang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Kanto Nishikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Masafumi Matsui
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Truong Quang Nguyen
- Institute of Ecology and Biological Resources, Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Feng Xie
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Cheng Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Janak Raj Khatiwada
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Baowei Zhang
- College of Life Science, Anhui University, Hefei, China
| | - Dajie Gong
- College of Life Science, Northwest Normal University, Lanzhou, China
| | - Yunming Mo
- Natural History Museum of Guangxi, Nanning, China
| | - Gang Wei
- Biodiversity Conservation Key Laboratory, Guiyang College, Guiyang, China
| | - Xiaohong Chen
- College of Life Science, Henan Normal University, Xinxiang, China
| | - Youhui Shen
- College of Life Science, Hunan Normal University, Changsha, China
| | - Daode Yang
- Institute of Wildlife Conservation, Central South University of Forestry & Technology, Changsha, China
| | - Rongchuan Xiong
- Department of Life Science, Liupanshui Normal University, Liupanshui, China
| | - Jianping Jiang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
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Parametric mapping using spectral analysis for 11C-PBR28 PET reveals neuroinflammation in mild cognitive impairment subjects. Eur J Nucl Med Mol Imaging 2018. [PMID: 29523926 PMCID: PMC5993844 DOI: 10.1007/s00259-018-3984-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE Neuroinflammation and microglial activation play an important role in amnestic mild cognitive impairment (MCI) and Alzheimer's disease. In this study, we investigated the spatial distribution of neuroinflammation in MCI subjects, using spectral analysis (SA) to generate parametric maps and quantify 11C-PBR28 PET, and compared these with compartmental and other kinetic models of quantification. METHODS Thirteen MCI and nine healthy controls were enrolled in this study. Subjects underwent 11C-PBR28 PET scans with arterial cannulation. Spectral analysis with an arterial plasma input function was used to generate 11C-PBR28 parametric maps. These maps were then compared with regional 11C-PBR28 VT (volume of distribution) using a two-tissue compartment model and Logan graphic analysis. Amyloid load was also assessed with 18F-Flutemetamol PET. RESULTS With SA, three component peaks were identified in addition to blood volume. The 11C-PBR28 impulse response function (IRF) at 90 min produced the lowest coefficient of variation. Single-subject analysis using this IRF demonstrated microglial activation in five out of seven amyloid-positive MCI subjects. IRF parametric maps of 11C-PBR28 uptake revealed a group-wise significant increase in neuroinflammation in amyloid-positive MCI subjects versus HC in multiple cortical association areas, and particularly in the temporal lobe. Interestingly, compartmental analysis detected group-wise increase in 11C-PBR28 binding in the thalamus of amyloid-positive MCI subjects, while Logan parametric maps did not perform well. CONCLUSIONS This study demonstrates for the first time that spectral analysis can be used to generate parametric maps of 11C-PBR28 uptake, and is able to detect microglial activation in amyloid-positive MCI subjects. IRF parametric maps of 11C-PBR28 uptake allow voxel-wise single-subject analysis and could be used to evaluate microglial activation in individual subjects.
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29
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Langkilde F, Kobus T, Fedorov A, Dunne R, Tempany C, Mulkern RV, Maier SE. Evaluation of fitting models for prostate tissue characterization using extended-range b-factor diffusion-weighted imaging. Magn Reson Med 2017; 79:2346-2358. [PMID: 28718517 DOI: 10.1002/mrm.26831] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 11/08/2022]
Abstract
PURPOSE To compare the fitting and tissue discrimination performance of biexponential, kurtosis, stretched exponential, and gamma distribution models for high b-factor diffusion-weighted images in prostate cancer. METHODS Diffusion-weighted images with 15 b-factors ranging from b = 0 to 3500 s/mm2 were obtained in 62 prostate cancer patients. Pixel-wise signal decay fits for each model were evaluated with the Akaike Information Criterion (AIC). Parameter values for each model were determined within normal prostate and the index lesion. Their potential to differentiate normal from cancerous tissue was investigated through receiver operating characteristic analysis and comparison with Gleason score. RESULTS The biexponential slow diffusion fraction fslow , the apparent kurtosis diffusion coefficient ADCK , and the excess kurtosis factor K differ significantly among normal peripheral zone (PZ), normal transition zone (TZ), tumor PZ, and tumor TZ. Biexponential and gamma distribution models result in the lowest AIC, indicating a superior fit. Maximum areas under the curve (AUCs) of all models ranged from 0.93 to 0.96 for the PZ and from 0.95 to 0.97 for the TZ. Similar AUCs also result from the apparent diffusion coefficient (ADC) of a monoexponential fit to a b-factor sub-range up to 1250 s/mm2 . For kurtosis and stretched exponential models, single parameters yield the highest AUCs, whereas for the biexponential and gamma distribution models, linear combinations of parameters produce the highest AUCs. Parameters with high AUC show a trend in differentiating low from high Gleason score, whereas parameters with low AUC show no such ability. CONCLUSION All models, including a monoexponential fit to a lower-b sub-range, achieve similar AUCs for discrimination of normal and cancer tissue. The biexponential model, which is favored statistically, also appears to provide insight into disease-related microstructural changes. Magn Reson Med 79:2346-2358, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Fredrik Langkilde
- Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Thiele Kobus
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Andriy Fedorov
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ruth Dunne
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Clare Tempany
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Robert V Mulkern
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Stephan E Maier
- Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.,Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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30
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Robinson JL, Jaslove JM, Murawski AM, Fazen CH, Brynildsen MP. An integrated network analysis reveals that nitric oxide reductase prevents metabolic cycling of nitric oxide by Pseudomonas aeruginosa. Metab Eng 2017; 41:67-81. [PMID: 28363762 DOI: 10.1016/j.ymben.2017.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/21/2016] [Accepted: 03/27/2017] [Indexed: 01/08/2023]
Abstract
Nitric oxide (NO) is a chemical weapon within the arsenal of immune cells, but is also generated endogenously by different bacteria. Pseudomonas aeruginosa are pathogens that contain an NO-generating nitrite (NO2-) reductase (NirS), and NO has been shown to influence their virulence. Interestingly, P. aeruginosa also contain NO dioxygenase (Fhp) and nitrate (NO3-) reductases, which together with NirS provide the potential for NO to be metabolically cycled (NO→NO3-→NO2-→NO). Deeper understanding of NO metabolism in P. aeruginosa will increase knowledge of its pathogenesis, and computational models have proven to be useful tools for the quantitative dissection of NO biochemical networks. Here we developed such a model for P. aeruginosa and confirmed its predictive accuracy with measurements of NO, O2, NO2-, and NO3- in mutant cultures devoid of Fhp or NorCB (NO reductase) activity. Using the model, we assessed whether NO was metabolically cycled in aerobic P. aeruginosa cultures. Calculated fluxes indicated a bottleneck at NO3-, which was relieved upon O2 depletion. As cell growth depleted dissolved O2 levels, NO3- was converted to NO2- at near-stoichiometric levels, whereas NO2- consumption did not coincide with NO or NO3- accumulation. Assimilatory NO2- reductase (NirBD) or NorCB activity could have prevented NO cycling, and experiments with ΔnirB, ΔnirS, and ΔnorC showed that NorCB was responsible for loss of flux from the cycle. Collectively, this work provides a computational tool to analyze NO metabolism in P. aeruginosa, and establishes that P. aeruginosa use NorCB to prevent metabolic cycling of NO.
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Affiliation(s)
- Jonathan L Robinson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Jacob M Jaslove
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Allison M Murawski
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Christopher H Fazen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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Marsot M, Béral M, Scoizec A, Mathevon Y, Durand B, Courcoul A. Herd-level risk factors for bovine tuberculosis in French cattle herds. Prev Vet Med 2016; 131:31-40. [DOI: 10.1016/j.prevetmed.2016.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 07/05/2016] [Accepted: 07/07/2016] [Indexed: 11/25/2022]
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32
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Fan Z, Calsolaro V, Atkinson RA, Femminella GD, Waldman A, Buckley C, Trigg W, Brooks DJ, Hinz R, Edison P. Flutriciclamide (18F-GE180) PET: First-in-Human PET Study of Novel Third-Generation In Vivo Marker of Human Translocator Protein. J Nucl Med 2016; 57:1753-1759. [DOI: 10.2967/jnumed.115.169078] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 05/10/2016] [Indexed: 12/27/2022] Open
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Robinson JL, Brynildsen MP. Discovery and dissection of metabolic oscillations in the microaerobic nitric oxide response network of Escherichia coli. Proc Natl Acad Sci U S A 2016; 113:E1757-66. [PMID: 26951670 PMCID: PMC4812703 DOI: 10.1073/pnas.1521354113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The virulence of many pathogens depends upon their ability to cope with immune-generated nitric oxide (NO·). In Escherichia coli, the major NO· detoxification systems are Hmp, an NO· dioxygenase (NOD), and NorV, an NO· reductase (NOR). It is well established that Hmp is the dominant system under aerobic conditions, whereas NorV dominates anaerobic conditions; however, the quantitative contributions of these systems under the physiologically relevant microaerobic regime remain ill defined. Here, we investigated NO· detoxification in environments ranging from 0 to 50 μM O2, and discovered a regime in which E. coli NO· defenses were severely compromised, as well as conditions that exhibited oscillations in the concentration of NO·. Using an integrated computational and experimental approach, E. coli NO· detoxification was found to be extremely impaired at low O2 due to a combination of its inhibitory effects on NorV, Hmp, and translational activities, whereas oscillations were found to result from a kinetic competition for O2 between Hmp and respiratory cytochromes. Because at least 777 different bacterial species contain the genetic requirements of this stress response oscillator, we hypothesize that such oscillatory behavior could be a widespread phenomenon. In support of this hypothesis,Pseudomonas aeruginosa, whose respiratory and NO· response networks differ considerably from those of E. coli, was found to exhibit analogous oscillations in low O2 environments. This work provides insight into how bacterial NO· defenses function under the low O2 conditions that are likely to be encountered within host environments.
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Affiliation(s)
- Jonathan L Robinson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
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34
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Robinson JL, Brynildsen MP. Construction and Experimental Validation of a Quantitative Kinetic Model of Nitric Oxide Stress in Enterohemorrhagic Escherichia coli O157:H7. Bioengineering (Basel) 2016; 3:E9. [PMID: 28952571 PMCID: PMC5597167 DOI: 10.3390/bioengineering3010009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 02/01/2016] [Indexed: 12/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are responsible for large outbreaks of hemorrhagic colitis, which can progress to life-threatening hemolytic uremic syndrome (HUS) due to the release of Shiga-like toxins (Stx). The presence of a functional nitric oxide (NO·) reductase (NorV), which protects EHEC from NO· produced by immune cells, was previously found to correlate with high HUS incidence, and it was shown that NorV activity enabled prolonged EHEC survival and increased Stx production within macrophages. To enable quantitative study of EHEC NO· defenses and facilitate the development of NO·-potentiating therapeutics, we translated an existing kinetic model of the E. coli K-12 NO· response to an EHEC O157:H7 strain. To do this, we trained uncertain model parameters on measurements of [NO·] and [O₂] in EHEC cultures, assessed parametric and prediction uncertainty with the use of a Markov chain Monte Carlo approach, and confirmed the predictive accuracy of the model with experimental data from genetic mutants lacking NorV or Hmp (NO· dioxygenase). Collectively, these results establish a methodology for the translation of quantitative models of NO· stress in model organisms to pathogenic sub-species, which is a critical step toward the application of these models for the study of infectious disease.
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Affiliation(s)
- Jonathan L Robinson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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Collange F, Fressard L, Pulcini C, Sebbah R, Peretti-Watel P, Verger P. General practitioners' attitudes and behaviors toward HPV vaccination: A French national survey. Vaccine 2016; 34:762-8. [PMID: 26752063 DOI: 10.1016/j.vaccine.2015.12.054] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/18/2015] [Accepted: 12/23/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE General practitioners (GPs) play a crucial role in human papillomavirus (HPV) vaccine acceptance in France. We sought to study: (1) GPs' perceptions of its risks and efficacy and their recommendation behavior; (2) the relative importance of factors associated with the frequency of their recommendations. METHODS Cross-sectional observational study in 2014 nested in a national panel of 1712 randomly selected GPs in private practice in France (response rate: 92.4%). We used model averaging to analyze the associations of self-reported frequency of GPs' HPV vaccine recommendations with their perception of its risk-benefit balance and their opinions about the utility of vaccines in general. RESULTS Overall, 72% of participants reported frequently recommending HPV vaccination; 60% considered that not enough is known about its risks. The model averaging showed that the factors most associated with infrequent recommendation of this vaccine by GPs were: unfavorable perceptions of its risk-benefit balance (OR=0.13; 95%CI=0.09-0.21; partial R(2)=0.10), a decision not to vaccinate one's own daughter(s) with this vaccine (OR=0.13; 95%CI=0.07-0.24; partial R(2)=0.05), and doubts about vaccine utility in general (OR=0.78; 95%CI=0.71-0.86; partial R(2)=0.03). CONCLUSION Although nearly three-quarters of French GPs frequently recommended the HPV vaccine, our findings indicate that a substantial percentage of them are hesitant about it. Doubts about its risks and efficacy strongly influence their recommendation behavior. More research is warranted to help design and evaluate tailored tools and multicomponent intervention strategies to address physician's hesitancy about this vaccine.
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Affiliation(s)
- Fanny Collange
- Aix Marseille University, URMITE, IRD 198, UMR CNRS 7278, INSERM 1095, Faculté de Médecine, 13005 Marseille, France; INSERM, UMR912 "Economics and Social Sciences Applied to Health & Analysis of Medical Information" (SESSTIM), 13006 Marseille, France; ORS PACA, Southeastern Health Regional Observatory, 13006 Marseille, France
| | - Lisa Fressard
- INSERM, UMR912 "Economics and Social Sciences Applied to Health & Analysis of Medical Information" (SESSTIM), 13006 Marseille, France; ORS PACA, Southeastern Health Regional Observatory, 13006 Marseille, France; Aix-Marseille University, IRD, UMR-S912, 13006 Marseille, France
| | - Céline Pulcini
- CHU de Nancy, Service de Maladies Infectieuses et Tropicales, Hôpitaux de Brabois, 54511 Vandœuvre-lès-Nancy cedex, France; Lorraine University, Paris Descartes University, EA 4360 Apemac, 54505 Vandœuvre-lès-Nancy cedex, France
| | - Rémy Sebbah
- Regional Unions of Healthcare Professionals (Southeastern Region) - Self-employed Physicians (URPS-ML PACA), 13006 Marseille, France
| | - Patrick Peretti-Watel
- INSERM, UMR912 "Economics and Social Sciences Applied to Health & Analysis of Medical Information" (SESSTIM), 13006 Marseille, France; ORS PACA, Southeastern Health Regional Observatory, 13006 Marseille, France; Aix-Marseille University, IRD, UMR-S912, 13006 Marseille, France
| | - Pierre Verger
- INSERM, UMR912 "Economics and Social Sciences Applied to Health & Analysis of Medical Information" (SESSTIM), 13006 Marseille, France; ORS PACA, Southeastern Health Regional Observatory, 13006 Marseille, France; Aix-Marseille University, IRD, UMR-S912, 13006 Marseille, France; INSERM, F-CRIN, Innovative Clinical Research Network in Vaccinology (I-REIVAC), GH Cochin Broca Hôtel Dieu, 75014 Paris, France.
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Marshall DJ, Rezende EL, Baharuddin N, Choi F, Helmuth B. Thermal tolerance and climate warming sensitivity in tropical snails. Ecol Evol 2015; 5:5905-19. [PMID: 26811764 PMCID: PMC4717333 DOI: 10.1002/ece3.1785] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/14/2015] [Accepted: 09/17/2015] [Indexed: 11/07/2022] Open
Abstract
Tropical ectotherms are predicted to be especially vulnerable to climate change because their thermal tolerance limits generally lie close to current maximum air temperatures. This prediction derives primarily from studies on insects and lizards and remains untested for other taxa with contrasting ecologies. We studied the HCT (heat coma temperatures) and ULT (upper lethal temperatures) of 40 species of tropical eulittoral snails (Littorinidae and Neritidae) inhabiting exposed rocky shores and shaded mangrove forests in Oceania, Africa, Asia and North America. We also estimated extremes in animal body temperature at each site using a simple heat budget model and historical (20 years) air temperature and solar radiation data. Phylogenetic analyses suggest that HCT and ULT exhibit limited adaptive variation across habitats (mangroves vs. rocky shores) or geographic locations despite their contrasting thermal regimes. Instead, the elevated heat tolerance of these species (HCT = 44.5 ± 1.8°C and ULT = 52.1 ± 2.2°C) seems to reflect the extreme temperature variability of intertidal systems. Sensitivity to climate warming, which was quantified as the difference between HCT or ULT and maximum body temperature, differed greatly between snails from sunny (rocky shore; Thermal Safety Margin, TSM = -14.8 ± 3.3°C and -6.2 ± 4.4°C for HCT and ULT, respectively) and shaded (mangrove) habitats (TSM = 5.1 ± 3.6°C and 12.5 ± 3.6°C). Negative TSMs in rocky shore animals suggest that mortality is likely ameliorated during extreme climatic events by behavioral thermoregulation. Given the low variability in heat tolerance across species, habitat and geographic location account for most of the variation in TSM and may adequately predict the vulnerability to climate change. These findings caution against generalizations on the impact of global warming across ectothermic taxa and highlight how the consideration of nonmodel animals, ecological transitions, and behavioral responses may alter predictions of studies that ignore these biological details.
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Affiliation(s)
- David J. Marshall
- Environmental and Life SciencesFaculty of ScienceUniversiti Brunei DarussalamGadongBE1410Brunei Darussalam
| | - Enrico L. Rezende
- Department of Life SciencesUniversity of RoehamptonHolybourne AvenueLondonSW15 4JDUK
| | - Nursalwa Baharuddin
- Environmental and Life SciencesFaculty of ScienceUniversiti Brunei DarussalamGadongBE1410Brunei Darussalam
- School of Marine Science and Environmental StudiesUniversiti Malaysia TerengganuTerengganu21030Malaysia
| | - Francis Choi
- Department of Marine and Environmental Sciences and School of Public Policy and Urban AffairsNortheastern UniversityBostonMassachusetts02115
| | - Brian Helmuth
- Department of Marine and Environmental Sciences and School of Public Policy and Urban AffairsNortheastern UniversityBostonMassachusetts02115
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Adolfsen KJ, Brynildsen MP. A Kinetic Platform to Determine the Fate of Hydrogen Peroxide in Escherichia coli. PLoS Comput Biol 2015; 11:e1004562. [PMID: 26545295 PMCID: PMC4636272 DOI: 10.1371/journal.pcbi.1004562] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/18/2015] [Indexed: 11/29/2022] Open
Abstract
Hydrogen peroxide (H2O2) is used by phagocytic cells of the innate immune response to kill engulfed bacteria. H2O2 diffuses freely into bacteria, where it can wreak havoc on sensitive biomolecules if it is not rapidly detoxified. Accordingly, bacteria have evolved numerous systems to defend themselves against H2O2, and the importance of these systems to pathogenesis has been substantiated by the many bacteria that require them to establish or sustain infections. The kinetic competition for H2O2 within bacteria is complex, which suggests that quantitative models will improve interpretation and prediction of network behavior. To date, such models have been of limited scope, and this inspired us to construct a quantitative, systems-level model of H2O2 detoxification in Escherichia coli that includes detoxification enzymes, H2O2-dependent transcriptional regulation, enzyme degradation, the Fenton reaction and damage caused by •OH, oxidation of biomolecules by H2O2, and repair processes. After using an iterative computational and experimental procedure to train the model, we leveraged it to predict how H2O2 detoxification would change in response to an environmental perturbation that pathogens encounter within host phagosomes, carbon source deprivation, which leads to translational inhibition and limited availability of NADH. We found that the model accurately predicted that NADH depletion would delay clearance at low H2O2 concentrations and that detoxification at higher concentrations would resemble that of carbon-replete conditions. These results suggest that protein synthesis during bolus H2O2 stress does not affect clearance dynamics and that access to catabolites only matters at low H2O2 concentrations. We anticipate that this model will serve as a computational tool for the quantitative exploration and dissection of oxidative stress in bacteria, and that the model and methods used to develop it will provide important templates for the generation of comparable models for other bacterial species.
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Affiliation(s)
- Kristin J Adolfsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, United States of America
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, United States of America
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Sabri O, Becker GA, Meyer PM, Hesse S, Wilke S, Graef S, Patt M, Luthardt J, Wagenknecht G, Hoepping A, Smits R, Franke A, Sattler B, Habermann B, Neuhaus P, Fischer S, Tiepolt S, Deuther-Conrad W, Barthel H, Schönknecht P, Brust P. First-in-human PET quantification study of cerebral α4β2* nicotinic acetylcholine receptors using the novel specific radioligand (−)-[ 18 F]Flubatine. Neuroimage 2015; 118:199-208. [DOI: 10.1016/j.neuroimage.2015.05.065] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 05/15/2015] [Accepted: 05/24/2015] [Indexed: 10/23/2022] Open
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Nicolas R, Sibon I, Hiba B. Accuracies and Contrasts of Models of the Diffusion-Weighted-Dependent Attenuation of the MRI Signal at Intermediate b-values. MAGNETIC RESONANCE INSIGHTS 2015; 8:11-21. [PMID: 26106263 PMCID: PMC4468950 DOI: 10.4137/mri.s25301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/23/2015] [Accepted: 04/26/2015] [Indexed: 11/24/2022]
Abstract
The diffusion-weighted-dependent attenuation of the MRI signal E(b) is extremely sensitive to microstructural features. The aim of this study was to determine which mathematical model of the E(b) signal most accurately describes it in the brain. The models compared were the monoexponential model, the stretched exponential model, the truncated cumulant expansion (TCE) model, the biexponential model, and the triexponential model. Acquisition was performed with nine b-values up to 2500 s/mm2 in 12 healthy volunteers. The goodness-of-fit was studied with F-tests and with the Akaike information criterion. Tissue contrasts were differentiated with a multiple comparison corrected nonparametric analysis of variance. F-test showed that the TCE model was better than the biexponential model in gray and white matter. Corrected Akaike information criterion showed that the TCE model has the best accuracy and produced the most reliable contrasts in white matter among all models studied. In conclusion, the TCE model was found to be the best model to infer the microstructural properties of brain tissue.
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Affiliation(s)
- Renaud Nicolas
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR 5536, CNRS-Université Bordeaux, Bordeaux Cedex, France. ; Aquitaine Institute for Cognitive and Integrative Neuroscience (INCIA), UMR 5287, CNRS-Université Bordeaux, Talence, France. ; Ecole Pratique des Hautes Etudes (EPHE), Laboratoire de Neurobiologie Intégrative et Adaptative, Bordeaux Cedex, France
| | - Igor Sibon
- Aquitaine Institute for Cognitive and Integrative Neuroscience (INCIA), UMR 5287, CNRS-Université Bordeaux, Talence, France. ; University Hospital (CHU) Bordeaux Pellegrin, NeuroVascular Unit, Bordeaux Cedex, France
| | - Bassem Hiba
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR 5536, CNRS-Université Bordeaux, Bordeaux Cedex, France. ; Aquitaine Institute for Cognitive and Integrative Neuroscience (INCIA), UMR 5287, CNRS-Université Bordeaux, Talence, France
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Wey HY, Wang C, Schroeder FA, Logan J, Price JC, Hooker JM. Kinetic Analysis and Quantification of [¹¹C]Martinostat for in Vivo HDAC Imaging of the Brain. ACS Chem Neurosci 2015; 6:708-15. [PMID: 25768025 DOI: 10.1021/acschemneuro.5b00066] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Epigenetic mechanisms mediated by histone deacetylases (HDACs) have been implicated in a wide-range of CNS disorders and may offer new therapeutic opportunities. In vivo evaluation of HDAC density and drug occupancy has become possible with [(11)C]Martinostat, which exhibits selectivity for a subset of class I/IIb HDAC enzymes. In this study, we characterize the kinetic properties of [(11)C]Martinostat in the nonhuman primate (NHP) brain in preparation for human neuroimaging studies. The goal of this work was to determine whether classic compartmental analysis techniques were appropriate and to further determine if arterial plasma is required for future NHP studies. Using an arterial plasma input function, several analysis approaches were evaluated for robust outcome measurements. [(11)C]Martinostat showed high baseline distribution volume (VT) ranging from 29.9 to 54.4 mL/cm(3) in the brain and large changes in occupancy (up to 99%) with a blocking dose approaching full enzyme saturation. An averaged nondisplaceable tissue uptake (VND) of 8.6 ± 3.7 mL/cm(3) suggests high specific binding of [(11)C]Martinostat. From a two-tissue compartment model, [(11)C]Martinostat exhibits a high K1 (averaged K1 of 0.65 mL/cm(3)/min) and a small k4 (average of 0.0085 min(-1)). Our study supports that [(11)C]Martinostat can be used to detect changes in HDAC density and occupancy in vivo and that simplified analysis not using arterial blood could be appropriate.
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Affiliation(s)
- Hsiao-Ying Wey
- Athinoula
A Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Changning Wang
- Athinoula
A Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Frederick A. Schroeder
- Athinoula
A Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jean Logan
- Center
for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York 10016, United States
| | - Julie C. Price
- Department
of Radiology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Jacob M. Hooker
- Athinoula
A Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
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Pharmacokinetic Analysis of (64)Cu-ATSM Dynamic PET in Human Xenograft Tumors in Mice. Diagnostics (Basel) 2015; 5:96-112. [PMID: 26854145 PMCID: PMC4665587 DOI: 10.3390/diagnostics5020096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/05/2015] [Accepted: 03/09/2015] [Indexed: 11/17/2022] Open
Abstract
UNLABELLED The aim of this study was to evaluate the feasibility to perform voxel-wise kinetic modeling on datasets obtained from tumor-bearing mice that underwent dynamic PET scans with (64)Cu-ATSM and extract useful physiological parameters. METHODS Tumor-bearing mice underwent 90-min dynamic PET scans with (64)Cu-ATSM and CT scans with contrast. Irreversible and reversible two-tissue compartment models were fitted to time activity curves (TACs) obtained from whole tumor volumes and compared using the Akaike information criterion (AIC). Based on voxel-wise pharmacokinetic analysis, parametric maps of model rate constants k₁, k₃ and Ki were generated and compared to (64)Cu-ATSM uptake. RESULTS Based on the AIC, an irreversible two-tissue compartment model was selected for voxel-wise pharmacokinetic analysis. Of the extracted parameters, k₁ (~perfusion) showed a strong correlation with early tracer uptake (mean spearman R = 0.88) 5 min post injection (pi). Moreover, positive relationships were found between late tracer uptake (90 min pi) and both k₃ and the net influx rate constant, Ki (mean spearman R = 0.56 and R = 0.86; respectively). CONCLUSION This study shows the feasibility to extract relevant parameters from voxel-wise pharmacokinetic analysis to be used for preclinical validation of (64)Cu-ATSM as a hypoxia-specific PET tracer.
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Nicolas G, Chevalier V, Tantely LM, Fontenille D, Durand B. A spatially explicit metapopulation model and cattle trade analysis suggests key determinants for the recurrent circulation of rift valley Fever virus in a pilot area of madagascar highlands. PLoS Negl Trop Dis 2014; 8:e3346. [PMID: 25474116 PMCID: PMC4256285 DOI: 10.1371/journal.pntd.0003346] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/14/2014] [Indexed: 11/19/2022] Open
Abstract
Rift Valley fever (RVF) is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. In 2008-2009, a RVF outbreak affected the whole Madagascar island, including the Anjozorobe district located in Madagascar highlands. An entomological survey showed the absence of Aedes among the potential RVF virus (RVFV) vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. No serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild RVF virus (RVFV) reservoir. However, a three years serological and virological follow-up in cattle showed a recurrent RVFV circulation. The objective of this study was to understand the key determinants of this unexpected recurrent transmission. To achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. Three scenarios that could explain the RVFV recurrent circulation in the area were analyzed: (i) RVFV overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii) a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii) combination of both above mentioned mechanisms. Multi-model inference methods resulted in a model incorporating both a low level RVFV winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. Predictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. These results appeared robust according to the sensitivity analysis. Interweaving between agricultural works in rice fields, seasonality of vector proliferation, and cattle exchange practices could be a key element for understanding RVFV circulation in this area of Madagascar highlands.
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Affiliation(s)
- Gaëlle Nicolas
- International Centre of Research in Agronomy for Development (CIRAD), ES Department– AGIRs Unit, Montpellier, France
- Paris-Est University, Anses, Laboratory for Animal Health, Epidemiology Unit, Maisons-Alfort, France
| | - Véronique Chevalier
- International Centre of Research in Agronomy for Development (CIRAD), ES Department– AGIRs Unit, Montpellier, France
| | | | - Didier Fontenille
- Research Institute for Development (IRD), MIVEGEC, Montpellier, France
| | - Benoît Durand
- Paris-Est University, Anses, Laboratory for Animal Health, Epidemiology Unit, Maisons-Alfort, France
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Roux P, Sagaon-Teyssier L, Lions C, Fugon L, Verger P, Carrieri MP. HCV seropositivity in inmates and in the general population: an averaging approach to establish priority prevention interventions. BMJ Open 2014; 4:e005694. [PMID: 25331969 PMCID: PMC4202016 DOI: 10.1136/bmjopen-2014-005694] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVES Despite the fact that a considerable portion of hepatitis C virus (HCV) positive individuals are viraemic, the risk of transmitting HCV to others is context dependent. Prison is a particularly risky environment as HCV prevention tools are often unavailable. Using data from a cross-sectional study conducted in centres for HCV testing in southeastern France, we aimed to compare the patterns of risk factors in HCV-positive inmates with those in the general population. SETTING 26 centres for HIV/HCV testing in southeastern France (23 in the general population and 3 in prison). PRIMARY OUTCOME MEASURE HCV seropositivity measured with ELISA test. METHODS A propensity score method to ensure that the general and inmate populations could be compared and a multimodel averaging to estimate the degree (strong, weak, none) of the association of a number of specific factors with HCV seropositivity in each group. RESULTS Among the 52,082 participants, HCV infection prevalence was 1.5% and 5.2% in the general (n=46,125) and inmate (n=5957) populations, respectively. In both populations, 'drug injection without snorting' and 'drug injection with snorting' were very strongly associated with HCV seropositivity. Among inmates, 'drug snorting alone' (OR (95% CI) 2.21 (1.39 to 3.52) was also a strong correlate while tattoos, piercings (OR (95% CI) 1.22 (0.92 to 1.61)) and the sharing of toiletry items (OR (95% CI) 1.44 (0.84 to 2.47)) were weak correlates. CONCLUSIONS The pattern of risk factors associated with HCV seropositivity is different between the general and prison populations, injection and snorting practices being more prevalent in the latter. Access to prevention measures in prisons is not only a public health issue but also a human right for inmates who deserve equity of care and prevention.
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Affiliation(s)
- P Roux
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
| | - L Sagaon-Teyssier
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
| | - C Lions
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
| | - L Fugon
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
- AIDES, Tour Essor, Pantin, France
| | - P Verger
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
| | - M P Carrieri
- INSERM UMR912 (SESSTIM), Marseille, France
- Université Aix Marseille, IRD, UMR-S912, Marseille, France
- ORS PACA, Observatoire Régional de la Santé Provence Alpes Côte d'Azur, Marseille, France
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Lang M, Summers S, Stelling J. Cutting the wires: modularization of cellular networks for experimental design. Biophys J 2014; 106:321-31. [PMID: 24411264 DOI: 10.1016/j.bpj.2013.11.2960] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/11/2013] [Accepted: 11/12/2013] [Indexed: 01/02/2023] Open
Abstract
Understanding naturally evolved cellular networks requires the consecutive identification and revision of the interactions between relevant molecular species. In this process, initially often simplified and incomplete networks are extended by integrating new reactions or whole subnetworks to increase consistency between model predictions and new measurement data. However, increased consistency with experimental data alone is not sufficient to show the existence of biomolecular interactions, because the interplay of different potential extensions might lead to overall similar dynamics. Here, we present a graph-based modularization approach to facilitate the design of experiments targeted at independently validating the existence of several potential network extensions. Our method is based on selecting the outputs to measure during an experiment, such that each potential network extension becomes virtually insulated from all others during data analysis. Each output defines a module that only depends on one hypothetical network extension, and all other outputs act as virtual inputs to achieve insulation. Given appropriate experimental time-series measurements of the outputs, our modules can be analyzed, simulated, and compared to the experimental data separately. Our approach exemplifies the close relationship between structural systems identification and modularization, an interplay that promises development of related approaches in the future.
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Affiliation(s)
- Moritz Lang
- Department of Biosystems Science and Engineering, ETH Zürich, and Swiss Institute of Bioinformatics, Basel, Switzerland.
| | - Sean Summers
- Automatic Control Laboratory, ETH Zürich, Zurich, Switzerland
| | - Jörg Stelling
- Department of Biosystems Science and Engineering, ETH Zürich, and Swiss Institute of Bioinformatics, Basel, Switzerland
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Hasdemir D, Hoefsloot HCJ, Westerhuis JA, Smilde AK. How informative is your kinetic model?: using resampling methods for model invalidation. BMC SYSTEMS BIOLOGY 2014; 8:61. [PMID: 24886662 PMCID: PMC4046068 DOI: 10.1186/1752-0509-8-61] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/14/2014] [Indexed: 01/09/2023]
Abstract
Background Kinetic models can present mechanistic descriptions of molecular processes within a cell. They can be used to predict the dynamics of metabolite production, signal transduction or transcription of genes. Although there has been tremendous effort in constructing kinetic models for different biological systems, not much effort has been put into their validation. In this study, we introduce the concept of resampling methods for the analysis of kinetic models and present a statistical model invalidation approach. Results We based our invalidation approach on the evaluation of a kinetic model’s predictive power through cross validation and forecast analysis. As a reference point for this evaluation, we used the predictive power of an unsupervised data analysis method which does not make use of any biochemical knowledge, namely Smooth Principal Components Analysis (SPCA) on the same test sets. Through a simulations study, we showed that too simple mechanistic descriptions can be invalidated by using our SPCA-based comparative approach until high amount of noise exists in the experimental data. We also applied our approach on an eicosanoid production model developed for human and concluded that the model could not be invalidated using the available data despite its simplicity in the formulation of the reaction kinetics. Furthermore, we analysed the high osmolarity glycerol (HOG) pathway in yeast to question the validity of an existing model as another realistic demonstration of our method. Conclusions With this study, we have successfully presented the potential of two resampling methods, cross validation and forecast analysis in the analysis of kinetic models’ validity. Our approach is easy to grasp and to implement, applicable to any ordinary differential equation (ODE) type biological model and does not suffer from any computational difficulties which seems to be a common problem for approaches that have been proposed for similar purposes. Matlab files needed for invalidation using SPCA cross validation and our toy model in SBML format are provided at http://www.bdagroup.nl/content/Downloads/software/software.php.
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Affiliation(s)
- Dicle Hasdemir
- Biosystems Data Analysis Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
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Qin Q, Huang AJ, Hua J, Desmond JE, Stevens RD, van Zijl PC. Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function. NMR IN BIOMEDICINE 2014; 27:116-28. [PMID: 24307572 PMCID: PMC3947417 DOI: 10.1002/nbm.3040] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/26/2013] [Accepted: 08/27/2013] [Indexed: 05/12/2023]
Abstract
Measurement of the cerebral blood flow (CBF) with whole-brain coverage is challenging in terms of both acquisition and quantitative analysis. In order to fit arterial spin labeling-based perfusion kinetic curves, an empirical three-parameter model which characterizes the effective impulse response function (IRF) is introduced, which allows the determination of CBF, the arterial transit time (ATT) and T(1,eff). The accuracy and precision of the proposed model were compared with those of more complicated models with four or five parameters through Monte Carlo simulations. Pseudo-continuous arterial spin labeling images were acquired on a clinical 3-T scanner in 10 normal volunteers using a three-dimensional multi-shot gradient and spin echo scheme at multiple post-labeling delays to sample the kinetic curves. Voxel-wise fitting was performed using the three-parameter model and other models that contain two, four or five unknown parameters. For the two-parameter model, T(1,eff) values close to tissue and blood were assumed separately. Standard statistical analysis was conducted to compare these fitting models in various brain regions. The fitted results indicated that: (i) the estimated CBF values using the two-parameter model show appreciable dependence on the assumed T(1,eff) values; (ii) the proposed three-parameter model achieves the optimal balance between the goodness of fit and model complexity when compared among the models with explicit IRF fitting; (iii) both the two-parameter model using fixed blood T1 values for T(1,eff) and the three-parameter model provide reasonable fitting results. Using the proposed three-parameter model, the estimated CBF (46 ± 14 mL/100 g/min) and ATT (1.4 ± 0.3 s) values averaged from different brain regions are close to the literature reports; the estimated T(1,eff) values (1.9 ± 0.4 s) are higher than the tissue T1 values, possibly reflecting a contribution from the microvascular arterial blood compartment.
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Affiliation(s)
- Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological
Science, Division of MR Research, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy
Krieger Institute, Baltimore, MD, USA
| | - Alan J. Huang
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy
Krieger Institute, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University,
Baltimore, MD, USA
| | - Jun Hua
- The Russell H. Morgan Department of Radiology and Radiological
Science, Division of MR Research, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy
Krieger Institute, Baltimore, MD, USA
| | - John E. Desmond
- Department of Neurology and Neurosurgery, The Johns Hopkins
University, Baltimore, MD, USA
| | - Robert D. Stevens
- The Russell H. Morgan Department of Radiology and Radiological
Science, Division of MR Research, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy
Krieger Institute, Baltimore, MD, USA
- Department of Neurology and Neurosurgery, The Johns Hopkins
University, Baltimore, MD, USA
- Department of Anesthesiology and Critical Care Medicine, The Johns
Hopkins University, Baltimore, MD, USA
| | - Peter C.M. van Zijl
- The Russell H. Morgan Department of Radiology and Radiological
Science, Division of MR Research, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy
Krieger Institute, Baltimore, MD, USA
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Cyran CC, Paprottka PM, Eisenblätter M, Clevert DA, Rist C, Nikolaou K, Lauber K, Wenz F, Hausmann D, Reiser MF, Belka C, Niyazi M. Visualization, imaging and new preclinical diagnostics in radiation oncology. Radiat Oncol 2014; 9:3. [PMID: 24387195 PMCID: PMC3903445 DOI: 10.1186/1748-717x-9-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 12/20/2013] [Indexed: 12/21/2022] Open
Abstract
Innovative strategies in cancer radiotherapy are stimulated by the growing knowledge on cellular and molecular tumor biology, tumor pathophysiology, and tumor microenvironment. In terms of tumor diagnostics and therapy monitoring, the reliable delineation of tumor boundaries and the assessment of tumor heterogeneity are increasingly complemented by the non-invasive characterization of functional and molecular processes, moving preclinical and clinical imaging from solely assessing tumor morphology towards the visualization of physiological and pathophysiological processes. Functional and molecular imaging techniques allow for the non-invasive characterization of tissues in vivo, using different modalities, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) and optical imaging (OI). With novel therapeutic concepts combining optimized radiotherapy with molecularly targeted agents focusing on tumor cell proliferation, angiogenesis, and cell death, the non-invasive assessment of tumor microcirculation and tissue water diffusion, together with strategies for imaging the mechanisms of cellular injury and repair is of particular interest. Characterizing the tumor microenvironment prior to and in response to irradiation will help to optimize the outcome of radiotherapy. These novel concepts of personalized multi-modal cancer therapy require careful pre-treatment stratification as well as a timely and efficient therapy monitoring to maximize patient benefit on an individual basis. Functional and molecular imaging techniques are key in this regard to open novel opportunities for exploring and understanding the underlying mechanisms with the perspective to optimize therapeutic concepts and translate them into a personalized form of radiotherapy in the near future.
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Affiliation(s)
- Clemens C Cyran
- Department of Clinical Radiology, Laboratory of Experimental Radiology, University of Munich Hospitals, Campus Großhadern, Marchioninistraße 15, 81377 Munich, Germany.
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Rezende EL, Diniz-Filho JAF. Phylogenetic analyses: comparing species to infer adaptations and physiological mechanisms. Compr Physiol 2013; 2:639-74. [PMID: 23728983 DOI: 10.1002/cphy.c100079] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Comparisons among species have been a standard tool in animal physiology to understand how organisms function and adapt to their surrounding environment. During the last two decades, conceptual and methodological advances from different fields, including evolutionary biology and systematics, have revolutionized the way comparative analyses are performed, resulting in the advent of modern phylogenetic statistical methods. This development stems from the realization that conventional analytical methods assume that observations are statistically independent, which is not the case for comparative data because species often resemble each other due to shared ancestry. By taking evolutionary history explicitly into consideration, phylogenetic statistical methods can account for the confounding effects of shared ancestry in interspecific comparisons, improving the reliability of standard approaches such as regressions or correlations in comparative analyses. Importantly, these methods have also enabled researchers to address entirely new evolutionary questions, such as the historical sequence of events that resulted in current patterns of form and function, which can only be studied with a phylogenetic perspective. Here, we provide an overview of phylogenetic approaches and their importance for studying the evolution of physiological processes and mechanisms. We discuss the conceptual framework underlying these methods, and explain when and how phylogenetic information should be employed. We then outline the difficulties and limitations inherent to comparative approaches and discuss potential problems researchers may encounter when designing a comparative study. These issues are illustrated with examples from the literature in which the incorporation of phylogenetic information has been useful, or even crucial, for inferences on how species evolve and adapt to their surrounding environment.
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Affiliation(s)
- Enrico L Rezende
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
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Zhao L, Ashek A, Wang L, Fang W, Dabral S, Dubois O, Cupitt J, Pullamsetti SS, Cotroneo E, Jones H, Tomasi G, Nguyen QD, Aboagye EO, El-Bahrawy MA, Barnes G, Howard LS, Gibbs JSR, Gsell W, He JG, Wilkins MR. Heterogeneity in lung (18)FDG uptake in pulmonary arterial hypertension: potential of dynamic (18)FDG positron emission tomography with kinetic analysis as a bridging biomarker for pulmonary vascular remodeling targeted treatments. Circulation 2013; 128:1214-24. [PMID: 23900048 DOI: 10.1161/circulationaha.113.004136] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a disease of progressive vascular remodeling, characterized by dysregulated growth of pulmonary vascular cells and inflammation. A prevailing view is that abnormal cellular metabolism, notably aerobic glycolysis that increases glucose demand, underlies the pathogenesis of PAH. Increased lung glucose uptake has been reported in animal models. Few data exist from patients with PAH. METHODS AND RESULTS Dynamic positron emission tomography imaging with fluorine-18-labeled 2-fluoro-2-deoxyglucose ((18)FDG) ligand with kinetic analysis demonstrated increased mean lung parenchymal uptake in 20 patients with PAH, 18 with idiopathic PAH (IPAH) (FDG score: 3.27±1.22), and 2 patients with connective tissue disease (5.07 and 7.11) compared with controls (2.02±0.71; P<0.05). Further compartment analysis confirmed increased lung glucose metabolism in IPAH. Lung (18)FDG uptake and metabolism varied within the IPAH population and within the lungs of individual patients, consistent with the recognized heterogeneity of vascular pathology in this disease. The monocrotaline rat PAH model also showed increased lung (18)FDG uptake, which was reduced along with improvements in vascular pathology after treatment with dicholoroacetate and 2 tyrosine kinase inhibitors, imatinib and sunitinib. Hyperproliferative pulmonary vascular fibroblasts isolated from IPAH patients exhibited upregulated glycolytic gene expression, along with increased cellular (18)FDG uptake; both were reduced by dicholoroacetate and imatinib. CONCLUSIONS Some patients with IPAH exhibit increased lung (18)FDG uptake. (18)FDG positron emission tomography imaging is a tool to investigate the molecular pathology of PAH and its response to treatment.
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Affiliation(s)
- Lan Zhao
- Centre for Pharmacology and Therapeutics, Experimental Medicine, Imperial College London, Hammersmith Hospital, London, UK (L.Z., A.A., L.W., O.D., J.C., E.C., H.J., G.B., M.R.W.); Department of Nuclear Medicine, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (W.F.); Max-Planck Institute for Heart and Lung Research and University of Giessen and Marburg Lung Center, German Center for Lung Research, Bad Nauheim, Germany (S.D., S.S.P.); Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK (G.T., Q.N., E.O.A.); Department of Histopathology, Imperial College London, UK (M.A.E.-B.); National Heart and Lung Institute, Imperial College London, and National Pulmonary Hypertension Service, Department of Cardiology, Hammersmith Hospital, London, UK (L.S.H., J.S.R.G.); Biological Imaging Centre, Medical Research Council Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, UK (W.G.); and Center for Diagnosis and Management of Pulmonary Vascular Diseases, Department of Cardiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (J.H.)
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Costa RP, Sjöström PJ, van Rossum MCW. Probabilistic inference of short-term synaptic plasticity in neocortical microcircuits. Front Comput Neurosci 2013; 7:75. [PMID: 23761760 PMCID: PMC3674479 DOI: 10.3389/fncom.2013.00075] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 05/17/2013] [Indexed: 11/25/2022] Open
Abstract
Short-term synaptic plasticity is highly diverse across brain area, cortical layer, cell type, and developmental stage. Since short-term plasticity (STP) strongly shapes neural dynamics, this diversity suggests a specific and essential role in neural information processing. Therefore, a correct characterization of short-term synaptic plasticity is an important step towards understanding and modeling neural systems. Phenomenological models have been developed, but they are usually fitted to experimental data using least-mean-square methods. We demonstrate that for typical synaptic dynamics such fitting may give unreliable results. As a solution, we introduce a Bayesian formulation, which yields the posterior distribution over the model parameters given the data. First, we show that common STP protocols yield broad distributions over some model parameters. Using our result we propose a experimental protocol to more accurately determine synaptic dynamics parameters. Next, we infer the model parameters using experimental data from three different neocortical excitatory connection types. This reveals connection-specific distributions, which we use to classify synaptic dynamics. Our approach to demarcate connection-specific synaptic dynamics is an important improvement on the state of the art and reveals novel features from existing data.
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Affiliation(s)
- Rui P Costa
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh Edinburgh, UK
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