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Perry M, Michgelsen J, Timmers R, Peetoom K, Koopmans R, Bakker C. Perceived barriers and solutions by generalist physicians to work towards timely young-onset dementia diagnosis. Aging Ment Health 2024; 28:262-267. [PMID: 37608741 DOI: 10.1080/13607863.2023.2248026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023]
Abstract
Objectives: Timely diagnosis of young-onset dementia (YOD) is an important prerequisite to initiate appropriate support. However, YOD diagnosis is often late. We aimed to explore the perspectives of referring general practitioners and occupational physicians, to better understand their barriers to YOD diagnosis and reveal potential solutions to facilitate timely diagnosis.Methods: We conducted 16 semi-structured qualitative interviews with general practitioners and occupational physicians in the Netherlands. Inductive thematic analysis was applied to the transcripts with a team including researchers from various (clinical) backgrounds.Results: Thematic analysis revealed three themes related to: (1) disease characteristics that hinder YOD recognition, being the low incidence and the fact that they mimic other prevalent conditions like burn-out and depression; (2) physicians' attitudes that delay YOD diagnosis, as fear of mis-diagnosis and therapeutic nihilism; and (3) proposed solutions to navigate the challenging YOD diagnostic trajectory including monitoring people with depression and burn-out to consider YOD when recovery stagnates, and more effective interprofessional collaboration.Conclusion: In this study, referring physicians confirmed barriers known to YOD diagnosis and suggested potential solutions to improve YOD diagnosis. Future prospective studies in people with a primary diagnosis of depression or burn-out may show whether these interventions are potentially effective.
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Affiliation(s)
- M Perry
- Department of Primary and Community Care, Center for Family Medicine, Geriatric Care and Public Health, Radboud University Nijmegen, Medical Center, Nijmegen, The Netherlands
| | - J Michgelsen
- Vilans, National Knowledge Centre for Expertise in Long-Term Care, Utrecht, The Netherlands
| | - R Timmers
- De Wever, Nursing Home, Tilburg, The Netherlands
| | - K Peetoom
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, The Netherlands
| | - R Koopmans
- Department of Primary and Community Care, Center for Family Medicine, Geriatric Care and Public Health, Radboud University Nijmegen, Medical Center, Nijmegen, The Netherlands
| | - C Bakker
- Department of Primary and Community Care, Center for Family Medicine, Geriatric Care and Public Health, Radboud University Nijmegen, Medical Center, Nijmegen, The Netherlands
- Florence, Mariahoeve, Center for Specialized Care in Early Onset Dementia, Den Haag, The Netherlands
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Kay DG, Stijl‐’t Hart E, Bakker C, Linkenkaer‐Hansen K, Sancilio FD, Ortiz JB, Groeneveld GJ, Poil S. A Quantitative‐EEG Assessment of Alpha‐1062, a Novel Pro‐Drug of Galantamine for the Treatment of Mild to Moderate Dementia Associated with Alzheimer’s Disease. Alzheimers Dement 2022. [DOI: 10.1002/alz.068223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | | | | | | | - Frederick D Sancilio
- Alpha Cognition Inc Vancouver BC Canada
- Florida Atlantic University Boca Raton FL USA
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3
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Renaud F, Mofenson LM, Bakker C, Dolk H, Leroy V, Namiba A, Sahin L, Shapiro R, Slogrove A, Thorne C, Vicari M, Low-Beer D, Doherty M. Surveillance of ARV safety in pregnancy and breastfeeding: towards a new framework. J Int AIDS Soc 2022; 25 Suppl 2:e25922. [PMID: 35851994 PMCID: PMC9294858 DOI: 10.1002/jia2.25922] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 04/29/2022] [Indexed: 01/04/2023] Open
Abstract
Introduction As new antiretrovirals (ARVs), including long‐acting ARVs for treatment and prevention, are approved and introduced, surveillance during pregnancy must become the safety net for evaluating birth outcomes, especially those that are rare and require large numbers of observations. Historically, drug pharmacovigilance in pregnancy has been limited and fragmented between different data sources, resulting in inadequate data to assess risk. The International Maternal Pediatric Adolescent AIDS Clinical Trials Network and World Health Organization convened a Workshop which reviewed strengths and weaknesses of existing programs and discussed an improved framework to integrate existing safety data sources and promote harmonization and digitalization. Discussion This paper highlights that although robust sources of safety data and surveillance programs exist, key challenges remain, including unknown denominators, reporting bias, under‐reporting (e.g. in voluntary registries), few data sources from resource‐limited settings (most are in North America and Europe), incomplete or inaccurate data (e.g. within routine medical records). However, recent experiences (e.g. with safety signals) and current innovations (e.g. electronic record use in resource‐limited settings and defining adverse outcomes) provide momentum and building blocks for a new framework for active surveillance of ARV safety in pregnancy. A public health approach should be taken using data from existing sources, including registries of pregnancy ARV exposure and birth defects; observational surveillance and cohort studies; clinical trials; and real‐world databases. Key facilitators are harmonization and standardization of outcomes, sharing of materials and tools, and data linkages between programs. Other key facilitators include the development of guidance to estimate sample size and duration of surveillance, ensuring strategic geographic diversity, bringing partners together to share information and engaging the community of women living with HIV. Conclusions Looking ahead, critical steps to safely introduce new ARVs include (1) adopting harmonized standards for measuring adverse maternal, birth and infant outcomes; (2) establishing surveillance centres of excellence in areas with high HIV prevalence with harmonized data collection and optimized electronic health records linking maternal/infant data; and (3) creating targets and evaluation goals for reporting progress on implementation and quality of surveillance in pregnancy. The platform will be leveraged to ensure that appropriate contributions and strategic actions by relevant stakeholders are implemented.
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Affiliation(s)
- Françoise Renaud
- Department of Global HIV, Hepatitis and Sexually Transmitted Infections Programmes, World Health Organization, Geneva, Switzerland
| | - Lynne M Mofenson
- Research Department, Elizabeth Glaser Pediatric AIDS Foundation, Washington, DC, USA
| | - Charlotte Bakker
- Seconded National Expert Translational Sciences Office Scientific Evidence Generation Department, European Medicines Agency, Amsterdam, The Netherlands
| | - Helen Dolk
- EUROmediCAT, Institute for Nursing and Health Research, Ulster University, Jordanstown, United Kingdom
| | - Valeriane Leroy
- Centre d'Epidémiologie et Recherche en Santé des POPulations (CERPOP), Inserm, Université de Toulouse Paul Sabatier, Toulouse, France
| | | | - Leyla Sahin
- Division of Pediatrics and Maternal Health, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Roger Shapiro
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Amy Slogrove
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Worcester, South Africa
| | - Claire Thorne
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Marissa Vicari
- HIV Programmes and Advocacy Department, International AIDS Society, Geneva, Switzerland
| | - Daniel Low-Beer
- Department of Global HIV, Hepatitis and Sexually Transmitted Infections Programmes, World Health Organization, Geneva, Switzerland
| | - Meg Doherty
- Department of Global HIV, Hepatitis and Sexually Transmitted Infections Programmes, World Health Organization, Geneva, Switzerland
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4
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Bakker C, van Esdonk MJ, Stuurman R(FE, Borghans LG, de Kam ML, van Gerven JM, Groeneveld GJ. Biperiden Challenge Model in Healthy Elderly as Proof-of-Pharmacology Tool: A Randomized, Placebo-Controlled Trial. J Clin Pharmacol 2021; 61:1466-1478. [PMID: 34021607 PMCID: PMC8596596 DOI: 10.1002/jcph.1913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/14/2021] [Indexed: 11/08/2022]
Abstract
Selective M1 muscarinic acetylcholine receptor (mAChR) agonists are being developed as symptomatic treatment for neurodegenerative and neuropsychiatric disorders that lead to cognitive dysfunction. Demonstrating cognition-enhancing effects in early-phase clinical development in healthy subjects is difficult. A challenge with the M1 mAChR antagonist biperiden could be used to demonstrate procognitive and pharmacological effects of selective M1 mAChR agonists. The aim of this study was to develop such a model. To this end, 12 healthy elderly subjects participated in a randomized, placebo-controlled, 3-way crossover study investigating tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) effects of 2 and 4 mg biperiden. Repeated PD assessments were performed using neurocognitive tasks and electrophysiological measurements. A population PK-PD model was developed. Four milligrams of biperiden showed significant impairment of sustained attention (-2.1 percentage point in adaptive tracking [95%CI, -3.043 to -1.148], verbal memory (2-3 fewer words recalled [95%CI, -5.9 to -0.2]) and working memory (up to a 50-millisecond increase in the n-back task reaction time [95%CI, 21.854-77.882]) compared with placebo. The PK data were best fitted by a 2-compartment model and showed high interoccasion and intersubject variability. Population PK-PD analysis quantified significant concentration-effect relationships for the n-back reaction time, n-back accuracy, and adaptive tracking. In conclusion, biperiden caused M1 mAChR-related dose- and concentration-dependent temporary declines in cognitive functioning. Therefore a biperiden pharmacological challenge model can be used for proof-of-pharmacology studies and to demonstrate cognition-enhancing effects of new cholinergic compounds that are being developed.
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Affiliation(s)
- Charlotte Bakker
- Centre for Human Drug ResearchLeidenThe Netherlands
- Leiden University Medical CentreLeidenThe Netherlands
| | | | | | | | | | | | - Geert Jan Groeneveld
- Centre for Human Drug ResearchLeidenThe Netherlands
- Leiden University Medical CentreLeidenThe Netherlands
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Bakker C, Prins S, Liptrot J, Hart EP, Klaassen ES, Brown GA, Brown A, Congreve M, Weir M, Marshall FH, Stevens J, Cross DM, Tasker T, Nathan PJ, Groeneveld GJ. Safety, pharmacokinetics and pharmacodynamics of HTL0009936, a selective muscarinic M 1 -acetylcholine receptor agonist: A randomized cross-over trial. Br J Clin Pharmacol 2021; 87:4439-4449. [PMID: 33891333 PMCID: PMC8596821 DOI: 10.1111/bcp.14872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 12/01/2022] Open
Abstract
AIMS HTL0009936 is a selective M1 muscarinic receptor agonist in development for cognitive dysfunction in Alzheimer's disease. Safety, tolerability and pharmacokinetics and exploratory pharmacodynamic effects of HTL0009936 administered by continuous IV infusion at steady state were investigated in elderly subjects with below average cognitive functioning (BACF). METHODS Part A was a four-treatment open label sequential study in healthy elderly investigating 10-83 mg HTL0009936 (IV) and a 24 mg HTL0009936 single oral dose. Part B was a five-treatment randomized, double-blind, placebo and physostigmine controlled cross-over study with IV HTL0009936 in elderly subjects with BACF. Pharmacodynamic assessments were performed using neurocognitive and electrophysiological tests. RESULTS Pharmacokinetics of HTL0009936 showed dose-proportional increases in exposure with a mean half-life of 2.4 hours. HTL0009936 was well-tolerated with transient dose-related adverse events (AEs). Small increases in mean systolic blood pressure of 7.12 mmHg (95% CI [3.99-10.24]) and in diastolic of 5.32 mmHg (95% CI [3.18-7.47]) were noted at the highest dose in part B. Overall, there was suggestive, but no definitive, positive or negative pharmacodynamic effects. Statistically significant effects were observed on P300 with HTL0009936 and adaptive tracking with physostigmine. CONCLUSIONS HTL0009936 showed well-characterized pharmacokinetics and single doses were safe and generally well-tolerated in healthy elderly subjects. Due to physostigmine tolerability issues and subject burden, the study design was changed and some pharmacodynamic assessments (neurocognitive) were performed at suboptimal drug exposures. Therefore no clear conclusions can be made on pharmacodynamic effects of HTL0009936, although an effect on P300 is suggestive of central target engagement.
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Affiliation(s)
- Charlotte Bakker
- Centre for Human Drug Research, Leiden, The Netherlands.,Leiden University Medical Center, Leiden, The Netherlands
| | - Samantha Prins
- Centre for Human Drug Research, Leiden, The Netherlands.,Leiden University Medical Center, Leiden, The Netherlands
| | | | - Ellen P Hart
- Centre for Human Drug Research, Leiden, The Netherlands
| | | | | | | | | | | | - Fiona H Marshall
- Sosei Heptares, Cambridge, UK.,MSD Research Laboratories (Merck & Co), Kenilworth, New Jersey, USA
| | - Jasper Stevens
- Centre for Human Drug Research, Leiden, The Netherlands.,University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | | | - Pradeep J Nathan
- Sosei Heptares, Cambridge, UK.,Department of Psychiatry, University of Cambridge, Cambridge, UK.,School of Psychological Sciences, Monash University, Australia
| | - Geert Jan Groeneveld
- Centre for Human Drug Research, Leiden, The Netherlands.,Leiden University Medical Center, Leiden, The Netherlands
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6
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Bakker C, Tasker T, Liptrot J, Hart EP, Klaassen ES, Doll RJ, Brown GA, Brown A, Congreve M, Weir M, Marshall FH, Cross DM, Groeneveld GJ, Nathan PJ. Safety, pharmacokinetics and exploratory pro-cognitive effects of HTL0018318, a selective M 1 receptor agonist, in healthy younger adult and elderly subjects: a multiple ascending dose study. Alzheimers Res Ther 2021; 13:87. [PMID: 33883008 PMCID: PMC8061066 DOI: 10.1186/s13195-021-00816-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/23/2021] [Indexed: 12/15/2022]
Abstract
Background The cholinergic system and M1 receptor remain an important target for symptomatic treatment of cognitive dysfunction. The selective M1 receptor partial agonist HTL0018318 is under development for the symptomatic treatment of Dementia’s including Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). We investigated the safety, tolerability, pharmacokinetics and exploratory pharmacodynamics of multiple doses of HTL0018318 in healthy younger adults and elderly subjects. Methods This randomised, double blind, placebo-controlled study was performed, investigating oral doses of 15–35 mg/day HTL0018318 or placebo in 7 cohorts of healthy younger adult (n = 36; 3 cohorts) and elderly (n = 50; 4 cohorts) subjects. Safety, tolerability and pharmacokinetic measurements were performed. Pharmacodynamics were assessed using a battery of neurocognitive tasks and electrophysiological biomarkers of synaptic and cognitive functions. Results HTL0018318 was generally well-tolerated in multiple doses up to 35 mg/day and were associated with mild or moderate cholinergic adverse events. There were modest increases in blood pressure and pulse rate when compared to placebo-treated subjects, with tendency for the blood pressure increase to attenuate with repeated dosing. There were no clinically significant observations or changes in blood and urine laboratory measures of safety or abnormalities in the ECGs and 24-h Holter assessments. HTL0018318 plasma exposure was dose-proportional over the range 15–35 mg. Maximum plasma concentrations were achieved after 1–2 h. The apparent terminal half-life of HTL0018318 was 16.1 h (± 4.61) in younger adult subjects and 14.3 h (± 2.78) in elderly subjects at steady state. HTL0018318 over the 10 days of treatment had significant effects on tests of short-term (working) memory (n-back) and learning (Milner maze) with moderate to large effect sizes. Conclusion Multiple doses of HTL0018138 showed well-characterised pharmacokinetics and were safe and generally well-tolerated in the dose range studied. Pro-cognitive effects on short-term memory and learning were demonstrated across the dose range. These data provide encouraging data in support of the development of HTL0018138 for cognitive dysfunction in AD and DLB. Trial registration Netherlands Trial Register identifier NTR5781. Registered on 22 March 2016. Supplementary Information The online version contains supplementary material available at 10.1186/s13195-021-00816-5.
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Affiliation(s)
- Charlotte Bakker
- Centre for Human Drug Research (CDHR), Zernikedreef 8, 2333 CL, Leiden, The Netherlands
| | - Tim Tasker
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | - Jan Liptrot
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | - Ellen P Hart
- Centre for Human Drug Research (CDHR), Zernikedreef 8, 2333 CL, Leiden, The Netherlands
| | - Erica S Klaassen
- Centre for Human Drug Research (CDHR), Zernikedreef 8, 2333 CL, Leiden, The Netherlands
| | - Robert Jan Doll
- Centre for Human Drug Research (CDHR), Zernikedreef 8, 2333 CL, Leiden, The Netherlands
| | | | - Alastair Brown
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | - Miles Congreve
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | - Malcolm Weir
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | | | | | - Geert Jan Groeneveld
- Centre for Human Drug Research (CDHR), Zernikedreef 8, 2333 CL, Leiden, The Netherlands. .,Leiden University Medical Centre, Leiden, The Netherlands.
| | - Pradeep J Nathan
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK.,Department of Psychiatry, University of Cambridge, Cambridge, UK.,School of Psychological Sciences, Monash University, Melbourne, Australia
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Bakker C, Tasker T, Liptrot J, Hart EP, Klaassen ES, Prins S, van der Doef TF, Brown GA, Brown A, Congreve M, Weir M, Marshall FH, Cross DM, Groeneveld GJ, Nathan PJ. First-in-man study to investigate safety, pharmacokinetics and exploratory pharmacodynamics of HTL0018318, a novel M 1 -receptor partial agonist for the treatment of dementias. Br J Clin Pharmacol 2021; 87:2945-2955. [PMID: 33351971 PMCID: PMC8359307 DOI: 10.1111/bcp.14710] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/09/2020] [Accepted: 12/16/2020] [Indexed: 12/23/2022] Open
Abstract
AIMS HTL0018318 is a selective M1 receptor partial agonist currently under development for the symptomatic treatment of cognitive and behavioural symptoms in Alzheimer's disease and other dementias. We investigated safety, tolerability, pharmacokinetics and exploratory pharmacodynamics (PD) of HTL0018318 following single ascending doses. METHODS This randomized, double-blind, placebo-controlled study in 40 healthy younger adult and 57 healthy elderly subjects, investigated oral doses of 1-35 mg HTL0018318. Pharmacodynamic assessments were performed using a battery of neurocognitive tasks and electrophysiological measurements. Cerebrospinal fluid concentrations of HTL0018318 and food effects on pharmacokinetics of HTL0018318 were investigated in an open label and partial cross-over design in 14 healthy subjects. RESULTS Pharmacokinetics of HTL0018318 were well-characterized showing dose proportional increases in exposure from 1-35 mg. Single doses of HTL0018318 were associated with mild dose-related adverse events of low incidence in both younger adult and elderly subjects. The most frequently reported cholinergic AEs included hyperhidrosis and increases in blood pressure up to 10.3 mmHg in younger adults (95% CI [4.2-16.3], 35-mg dose) and up to 11.9 mmHg in elderly subjects (95% CI [4.9-18.9], 15-mg dose). There were no statistically significant effects on cognitive function but the study was not powered to detect small to moderate effect sizes of clinical relevance. CONCLUSION HTL0018318 showed well-characterized pharmacokinetics and following single doses were generally well tolerated in the dose range studied. These provide encouraging data in support of the development for HTL0018318 for Alzheimer's disease and other dementias.
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Affiliation(s)
| | | | | | - Ellen P Hart
- Centre for Human Drug Research (CDHR), Leiden, Netherlands
| | | | - Samantha Prins
- Centre for Human Drug Research (CDHR), Leiden, Netherlands
| | | | | | | | | | | | | | | | - Geert Jan Groeneveld
- Centre for Human Drug Research (CDHR), Leiden, Netherlands.,Leiden University Medical Centre, Leiden, The Netherlands
| | - Pradeep J Nathan
- Sosei Heptares, Cambridge, UK.,Department of Psychiatry, University of Cambridge, UK.,School of Psychological Sciences, Monash University, Australia
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Bakker C, van der Aart J, Hart EP, Klaassen ES, Bergmann KR, van Esdonk MJ, Kay DG, Groeneveld GJ. Safety, pharmacokinetics, and pharmacodynamics of Gln-1062, a prodrug of galantamine. Alzheimers Dement (N Y) 2020; 6:e12093. [PMID: 33083515 PMCID: PMC7551138 DOI: 10.1002/trc2.12093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/26/2020] [Accepted: 09/11/2020] [Indexed: 11/07/2022]
Abstract
Introduction Gln-1062 (MEMOGAIN) is an intranasally administered lipophilic prodrug of galantamine. Based on high brain-to-blood concentrations observed in pre-clinical studies, Gln-1062 is expected to have superior cognitive efficacy compared to oral galantamine. Methods Forty-eight healthy elderly subjects were randomized 12:4 to Gln-1062 (5.5, 11, or 22 mg, b.i.d., for 7 days) or placebo. Safety, tolerability, pharmacokinetics, and pharmacodynamics were assessed repeatedly. Pharmacokinetics were compared with 16 mg oral galantamine. Results Gln-1062 up to 22 mg, b.i.d., was well tolerated. Gln-1062 plasma concentrations increased immediately following dosing (median Tmax of 0.5 hour [range 0.5-1.0]). Cmax and AUC0-last increased in a dose-linear manner over all three dose levels. Gln-1062 was rapidly cleaved into galantamine. Gln-1062 significantly improved adaptive tracking (sustained attention) with 1.95% (95% confidence interval [CI] 0.630-3.279, P = 0.0055) compared to placebo after correction for individual baseline performance. Discussion Gln-1062 was considered to be safe and caused fewer gastrointestinal side effects than oral galantamine. Gln-1062 behaved pharmacokinetically as expected and improved performance on cognitive tests.
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Affiliation(s)
| | | | - Ellen P Hart
- Centre for Human Drug Research Leiden The Netherlands
| | | | | | | | | | - Geert Jan Groeneveld
- Centre for Human Drug Research Leiden The Netherlands.,Department of Anesthesiology Leiden University Medical Centre Leiden The Netherlands
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Affiliation(s)
- S. Das
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - M. Lee Bowers
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - C. Bakker
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - A. Cacciuto
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
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10
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Zhang A, Dhruv P, Choi P, Bakker C, Koffel J, Anderson D. A Systematic Literature Review of Patients with Carotid Web and Acute Ischemic Stroke. J Vasc Surg 2019. [DOI: 10.1016/j.jvs.2019.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Boon MR, Hanssen MJW, Brans B, Hülsman CJM, Hoeks J, Nahon KJ, Bakker C, van Klinken JB, Havekes B, Schaart G, Jazet IM, Rensen PCN, van Marken Lichtenbelt WD. Effect of L-arginine on energy metabolism, skeletal muscle and brown adipose tissue in South Asian and Europid prediabetic men: a randomised double-blinded crossover study. Diabetologia 2019; 62:112-122. [PMID: 30377712 PMCID: PMC6290676 DOI: 10.1007/s00125-018-4752-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/06/2018] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS Individuals of South Asian origin are at increased risk of developing type 2 diabetes mellitus and associated comorbidities compared with Europids. Disturbances in energy metabolism may contribute to this increased risk. Skeletal muscle and possibly also brown adipose tissue (BAT) are involved in human energy metabolism and nitric oxide (NO) is suggested to play a pivotal role in regulating mitochondrial biogenesis in both tissues. We aimed to investigate the effects of 6 weeks of supplementation with L-arginine, a precursor of NO, on energy metabolism by BAT and skeletal muscle, as well as glucose metabolism in South Asian men compared with men of European descent. METHODS We included ten Dutch South Asian men (age 46.5 ± 2.8 years, BMI 30.1 ± 1.1 kg/m2) and ten Dutch men of European descent, that were similar with respect to age and BMI, with prediabetes (fasting plasma glucose level 5.6-6.9 mmol/l or plasma glucose levels 2 h after an OGTT 7.8-11.1 mmol/l). Participants took either L-arginine (9 g/day) or placebo orally for 6 weeks in a randomised double-blind crossover study. Participants were eligible to participate in the study when they were aged between 40 and 55 years, had a BMI between 25 and 35 kg/m2 and did not have type 2 diabetes. Furthermore, ethnicity was defined as having four grandparents of South Asian or white European origin, respectively. Blinding of treatment was done by the pharmacy (Hankintatukku) and an independent researcher from Leiden University Medical Center randomly assigned treatments by providing a coded list. All people involved in the study as well as participants were blinded to group assignment. After each intervention, glucose tolerance was determined by OGTT and basal metabolic rate (BMR) was determined by indirect calorimetry; BAT activity was assessed by cold-induced [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography-computed tomography scanning. In addition, a fasting skeletal muscle biopsy was taken and analysed ex vivo for respiratory capacity using a multisubstrate protocol. The primary study endpoint was the effect of L-arginine on BAT volume and activity. RESULTS L-Arginine did not affect BMR, [18F]FDG uptake by BAT or skeletal muscle respiration in either ethnicity. During OGTT, L-arginine lowered plasma glucose concentrations (AUC0-2 h - 9%, p < 0.01), insulin excursion (AUC0-2 h - 26%, p < 0.05) and peak insulin concentrations (-26%, p < 0.05) in Europid but not South Asian men. This coincided with enhanced cold-induced glucose oxidation (+44%, p < 0.05) in Europids only. Of note, in skeletal muscle biopsies several respiration states were consistently lower in South Asian men compared with Europid men. CONCLUSIONS/INTERPRETATION L-Arginine supplementation does not affect BMR, [18F]FDG uptake by BAT, or skeletal muscle mitochondrial respiration in Europid and South Asian overweight and prediabetic men. However, L-arginine improves glucose tolerance in Europids but not in South Asians. Furthermore, South Asian men have lower skeletal muscle oxidative capacity than men of European descent. FUNDING This study was funded by the EU FP7 project DIABAT, the Netherlands Organization for Scientific Research, the Dutch Diabetes Research Foundation and the Dutch Heart Foundation. TRIAL REGISTRATION ClinicalTrials.gov NCT02291458.
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Affiliation(s)
- Mariëtte R Boon
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands.
- Dept of Medicine, Division of Endocrinology, post zone C7Q, Leiden University Medical Center, P. O. Box 9600, 2300 RC, Leiden, the Netherlands.
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
| | - Mark J W Hanssen
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Boudewijn Brans
- Dept of Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Cindy J M Hülsman
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Joris Hoeks
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Kimberly J Nahon
- Dept of Medicine, Division of Endocrinology, post zone C7Q, Leiden University Medical Center, P. O. Box 9600, 2300 RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Charlotte Bakker
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Jan B van Klinken
- Dept of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Bas Havekes
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
- Dept of Internal Medicine, Division of Endocrinology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Gert Schaart
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Ingrid M Jazet
- Dept of Medicine, Division of Endocrinology, post zone C7Q, Leiden University Medical Center, P. O. Box 9600, 2300 RC, Leiden, the Netherlands
| | - Patrick C N Rensen
- Dept of Medicine, Division of Endocrinology, post zone C7Q, Leiden University Medical Center, P. O. Box 9600, 2300 RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Wouter D van Marken Lichtenbelt
- Dept of Human Biology & Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
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Millenaar J, de Vugt M, Bakker C, van Vliet D, Pijnenburg Y, Koopmans R, Verhey F. O1.06: The impact of young onset dementia on caregivers compared to late onset dementia: Results from the NeedYD study. Eur Geriatr Med 2014. [DOI: 10.1016/s1878-7649(14)70089-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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van Vliet D, de Vugt ME, Bakker C, Pijnenburg YAL, Vernooij-Dassen MJFJ, Koopmans RTCM, Verhey FRJ. Time to diagnosis in young-onset dementia as compared with late-onset dementia. Psychol Med 2013; 43:423-432. [PMID: 22640548 DOI: 10.1017/s0033291712001122] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The extent to which specific factors influence diagnostic delays in dementia is unclear. Therefore, the aim of the present study was to compare duration from symptom onset to diagnosis for young-onset dementia (YOD) and late-onset dementia (LOD) and to assess the effect of age at onset, type of dementia, gender, living situation, education and family history of dementia on this duration. METHOD Data on 235 YOD and 167 LOD patients collected from caregivers from two prospective cohort studies were used. Multiple linear regression analysis was performed. RESULTS The duration between symptom onset and the diagnosis of YOD exceeded that of LOD by an average of 1.6 years (2.8 v. 4.4 years). Young age and being diagnosed with frontotemporal dementia were related to increases in the time to diagnosis. Subjects with vascular dementia experienced shorter time to diagnosis. CONCLUSIONS There is a need to raise special awareness of YOD to facilitate a timely diagnosis.
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Affiliation(s)
- D van Vliet
- School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University Medical Centre, Maastricht, The Netherlands
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van den Bosch M, van den Berg C, de Leeuw H, Bakker C, Moman M, van Vulpen M, Lagendijk J, Moerland M. QUANTIFICATION OF MR IMAGE ARTEFACTS INDUCED BY IMPLANT ROBOT FOR PERMANENT PROSTATE BRACHYTHERAPY. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72858-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Raaymakers B, Van der Heide U, Raaijmakers A, Overweg J, Brown K, Welleweerd J, Bakker C, Lagendijk J. 226 Design of the MRI accelerator. Radiother Oncol 2005. [DOI: 10.1016/s0167-8140(05)81203-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Lagendijk J, Raaymakers B, van der Heide U, Overweg J, Brown K, Bakker C, Raaijmakers A, Vulpen M, Welleweerd J, Jürgenliemk-Schulz I. MO-E-J-6B-03: In Room Magnetic Resonance Imaging Guided Radiotherapy (MRIgRT). Med Phys 2005. [DOI: 10.1118/1.1998294] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Bakker C, Blair JM, Knapp AK. Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands? Oecologia 2003; 137:385-91. [PMID: 12955488 DOI: 10.1007/s00442-003-1360-y] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2002] [Indexed: 10/26/2022]
Abstract
Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison ( Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in grazed grasslands were evaluated: (1) bison grazing enhances levels of resource (light and N) availability, enabling species that depend on higher resource availability to co-occur; (2) spatial heterogeneity in resource availability is enhanced by bison, enabling coexistence of a greater number of plant species; (3) increased species turnover (i.e. increased species colonization and establishment) in grazed grassland is associated with enhanced plant species richness. We measured availability and spatial heterogeneity in light, water and N, and calculated species turnover from long-term data in grazed and ungrazed sites in a North American tallgrass prairie. Both regression and path analyses were performed to evaluate the potential of the three hypothesized mechanisms to explain observed patterns of plant species richness under field conditions. Experimental grazing by bison increased plant species richness by 25% over an 8-year period. Neither heterogeneity nor absolute levels of soil water or available N were related to patterns of species richness in grazed and ungrazed sites. However, high spatial heterogeneity in light and higher rates of species turnover were both strongly related to increases in plant species richness in grazed areas. This suggests that creation of a mosaic of patches with high and low biomass (the primary determinant of light availability in mesic grasslands) and promotion of a dynamic species pool are the most important mechanisms by which grazers affect species richness in high productivity grasslands.
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Affiliation(s)
- C Bakker
- Department of Ecology and Physiology of Plants, Free University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
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Vallero MVG, Lens PNL, Bakker C, Lettinga G. Sulfidogenic volatile fatty acid degradation in a baffled reactor. Water Sci Technol 2003; 48:81-88. [PMID: 14518858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effect of staging the sludge bed on volatile fatty acid degradation by sulfidogenic reactors was evaluated in a baffled reactor. In a 5.4 l baffled reactor, containing three equal compartments, a volatile fatty acid (VFA) mixture (acetate:propionate:butyrate ratio 1:2:2 on COD basis; pH 8) was treated under mesophilic (30 degrees C) and sulfidogenic (COD:SO4(2-) ratio: 0.5) conditions for 38 days. At a specific sludge loading rate of 0.50 g COD.gVSS(-1) x d(-1), a COD and sulfate removal of 85% and 30%, respectively, was obtained. In the baffled reactor, staging of the sulfidogenic VFA degradation occurred. Propionate and butyrate were mainly degraded in the first compartment. Their degradation was incomplete, resulting in elevated acetate concentrations in compartment I. In the second and third compartment of the baffled reactor, a net degradation of acetate took place. Acetate was the sole substrate present in compartment III and residual acetate concentrations of about 200 mg/l were present in the effluent at a specific sludge loading of 0.50 g COD x gVSS(-1) x d(-1). Sludges with different maximum specific VFA and acetate degrading activities developed in the first and second compartment. These maximal specific activities were almost equal for sludge present in compartment II and III.
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Affiliation(s)
- M V G Vallero
- Sub-department of Environmental Technology, Wageningen University and Research Centre, Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
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Tamanini F, Kirkpatrick LL, Schonkeren J, van Unen L, Bontekoe C, Bakker C, Nelson DL, Galjaard H, Oostra BA, Hoogeveen AT. The fragile X-related proteins FXR1P and FXR2P contain a functional nucleolar-targeting signal equivalent to the HIV-1 regulatory proteins. Hum Mol Genet 2000; 9:1487-93. [PMID: 10888599 DOI: 10.1093/hmg/9.10.1487] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fragile X syndrome is caused by the absence of the fragile X mental-retardation protein (FMRP). FMRP and the fragile X-related proteins 1 and 2 (FXR1P and FXR2P) form a gene family with functional similarities, such as RNA binding, polyribosomal association and nucleocytoplasmic shuttling. In a previous study, we found that FMRP and FXR1P shuttle between cytoplasm and nucleoplasm, while FXR2P shuttles between cytoplasm and nucleolus. The nuclear and nucleolar-targeting properties of these proteins were investigated further. Here, we show that FXR2P contains in its C-terminal part, a stretch of basic amino acids 'RPQRRNRSRRRRFR' that resemble the nucleolar-targeting signal (NoS) of the viral protein Rev. This particular sequence is also present within exon 15 of the FXR1 gene. This exon undergoes alternative splicing and is therefore only present in some of the FXR1P isoforms. We investigated the intracellular distribution of various FXR1P isoforms with (iso-e and iso-f) and without (iso-d) the potential NoS in transfected COS cells treated with the nuclear export inhibitor leptomycin-B. Both iso-e and iso-f showed a nucleolar localization, as observed for FXR2P; iso-d was detected in the nucleo-plasm outside the nucleoli. Further, when a labelled 16-residue synthetic peptide corresponding to the NoS of FXR1P was added to human fibroblast cultures a clear nucleolar signal was observed. Based on these data we argue that the intranuclear distribution of FXR2P and FXR1P isoforms is very likely to be mediated by a similar NoS localized in their C-terminal region. This domain is absent in some FXR1P isoforms as well as in all FMRP isoforms, suggesting functional differences for this family of proteins, possibly related to RNA metabolism in different tissues.
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Affiliation(s)
- F Tamanini
- Department of Clinical Genetics and Centre for Biomedical Genetics, Erasmus University, Rotterdam, The Netherlands
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Musumeci SA, Bosco P, Calabrese G, Bakker C, De Sarro GB, Elia M, Ferri R, Oostra BA. Audiogenic seizures susceptibility in transgenic mice with fragile X syndrome. Epilepsia 2000; 41:19-23. [PMID: 10643918 DOI: 10.1111/j.1528-1157.2000.tb01499.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate their susceptibility to audiogenic seizures, five groups of knockout mice with various forms of fragile X genetic involvement [hemizygous males (n = 46), and homozygous (n = 38) and heterozygous females (n = 45), and their normal male (n = 45) and female (n = 52) littermates] were studied. METHODS All mouse groups were tested at ages 17, 22, 35, and 45 days. Audiogenic seizure susceptibility was scored, and the analysis of variance was used for the evaluation of the effects of age and genetic condition on seizure severity score (SSS). RESULTS All groups of knockout fragile X mice exhibited SSSs significantly higher than those observed in their wild-type littermates; among knockout mice, hemizygous males and homozygous females showed the highest SSSs. Hemizygous males showed higher SSSs with increasing age, from 17 to 45 days; homozygous females showed a peak at age 22 days, followed by a decrease; finally, heterozygous females had their highest SSSs at age 17 days. CONCLUSIONS This study demonstrates that an increased susceptibility to audiogenic seizures is present in fragile X knockout mice at all the ages tested. These results support the validity of this animal model also for epilepsy and seizures in the human fragile X syndrome.
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Affiliation(s)
- S A Musumeci
- Department of Neurology, Oasi Institute for Research on Mental Retardation and Brain Aging, Troina, Italy.
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Tamanini F, Van Unen L, Bakker C, Sacchi N, Galjaard H, Oostra BA, Hoogeveen AT. Oligomerization properties of fragile-X mental-retardation protein (FMRP) and the fragile-X-related proteins FXR1P and FXR2P. Biochem J 1999; 343 Pt 3:517-23. [PMID: 10527928 PMCID: PMC1220581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The absence of fragile-X mental-retardation protein (FMRP) results in fragile-X syndrome. Two other fragile-X-related (FXR) proteins have been described, FXR1P and FXR2P, which are both very similar in amino acid sequence to FMRP. Interaction between the three proteins as well as with themselves has been demonstrated. The FXR proteins are believed to play a role in RNA metabolism. To characterize a possible functional role of the interacting proteins the complex formation of the FXR proteins was studied in mammalian cells. Double immunofluorescence analysis in COS cells over-expressing either FMRP ISO12/FXR1P or FMRP ISO12/FXR2P confirmed heterotypic interactions. However, Western-blotting studies on cellular homogenates containing physiological amounts of the three proteins gave different indications. Gel-filtration experiments under physiological as well as EDTA conditions showed that the FXR proteins were in complexes of >600 kDa, as parts of messenger ribonuclear protein (mRNP) particles associated with polyribosomes. Salt treatment shifted FMRP, FXR1P and FXR2P into distinct intermediate complexes, with molecular masses between 200 and 300 kDa. Immunoprecipitations of FMRP as well as FXR1P from the dissociated complexes revealed that the vast majority of the FXR proteins do not form heteromeric complexes. Further analysis by [(35)S]methionine labelling in vivo followed by immunoprecipitation indicated that no proteins other than the FXR proteins were present in these complexes. These results suggest that the FXR proteins form homo-multimers preferentially under physiological conditions in mammalian cells, and might participate in mRNP particles with separate functions.
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Affiliation(s)
- F Tamanini
- Department of Clinical Genetics and Centre for Biomedical Genetics, Erasmus University, PO Box 1738, 3000 DR Rotterdam, The Netherlands
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Abstract
The fragile X [fra(X)] syndrome is manifested phenotypically as a developmental disability comprised mainly of moderate-to-severe mental retardation (MR). Deficits are especially evident in auditory and visual short-term memory. Recently, an FMR1 knockout mouse developed by the Dutch-Belgian Fragile X Consortium demonstrated significantly lower visual-spatial abilities than littermate controls. We wondered if these results were associated with learning per se or to performance deficits only. Thus, we examined learning and memory in male FMR1 knockout mice crossbred from Fvb and E129 strains, and in male Fvb control mice, using operant conditioning techniques. In Experiment 1, we demonstrated that two aged male FMR1 knockouts could acquire the necessary bar-press response to discriminate visual (L+) and auditory (N+) stimuli. In Experiment 2, we showed that three naive male knockouts and two naive male controls, all 12 weeks old, also learned to discriminate L+ and N+. A third component, a complex discrimination task, during which light and noise were presented concurrently without reinforcement (LN-) was added to each session. All knockouts acquired both L+ and N+ discriminative responses in fewer sessions and with higher discrimination ratios than either control. Moreover, all knockouts exhibited the typical response pattern associated with complex discrimination (LN-) tasks. However, neither control made the complex discrimination. Our findings were unexpected and raise issues concerning FMR1 mouse strains and their cognitive-behavioral testing.
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Affiliation(s)
- G S Fisch
- Department of Epidemiology and Public Health, and the Child Study Center, Yale University, New Haven, Connecticut, USA
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Jansen PL, Bosma PJ, Bakker C, Lems SP, Slooff MJ, Haagsma EB. Persistent unconjugated hyperbilirubinemia after liver transplantation due to an abnormal bilirubin UDP-glucuronosyltransferase gene promoter sequence in the donor. J Hepatol 1997; 27:1-5. [PMID: 9252066 DOI: 10.1016/s0168-8278(97)80272-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND/AIMS Gilbert's syndrome is genetically characterized by an extra TA element in the TATAA-box of the promotor region upstream of the bilirubin UDP-glucuronosyltransferase (UGT1A) coding region (Bosma et al. N Engl J Med 1995; 333: 1171-5). Persistent unconjugated hyperbilirubinemia is occasionally observed in liver transplant recipients with an otherwise normal liver function. We postulate that these patients could have received a liver from a donor with the Gilbert's syndrome genotype. Therefore, we investigated the UGT1A-gene TATAA-box in DNA from liver graft donors of jaundiced and non-jaundiced recipients. METHODS DNA was obtained from stored donor lymphocytes and the number of TA elements in the TATAA-box of the UGT1A-gene promotor region was analyzed by polymerase chain-reaction. RESULTS We observed two liver transplant recipients with persistent unconjugated hyperbilirubinemia. They received liver grafts from donors who were homozygous for an abnormal A(TA)7TAA-box in the UGT1A-gene. Four of 10 non-jaundiced recipients received livers from donors who were homozygous for the normal A(TA)6TAA-box and six received livers from donors who were heterozygous with a normal A(TA)6TAA-box on one allele and a prolonged A(TA)7TAA-box on the other allele. CONCLUSIONS This study shows that liver graft recipients with persistent unconjugated hyperbilirubinemia may have received a liver from a donor with an abnormal TATAA-box in the bilirubin UGT1A-gene promotor region.
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Affiliation(s)
- P L Jansen
- Division of Hepatology and Gastroenterology, University Hospital, Groningen, The Netherlands.
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Van Der Veere CN, Schoemaker B, Bakker C, Van Der Meer R, Jansen PL, Elferink RP. Influence of dietary calcium phosphate on the disposition of bilirubin in rats with unconjugated hyperbilirubinemia. Hepatology 1996; 24:620-6. [PMID: 8781334 DOI: 10.1002/hep.510240326] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The aim of this study was to test a possible form of therapy that could be used in the management of unconjugated hyperbilirubinemia. We hypothesized that unconjugated bilirubin (UCB) can permeate the intestinal wall and can thus be secreted with the feces. We have previously observed that UCB binds to amorphous calcium phosphate in vitro. Orally ingested amorphous calcium phosphate may act as a trapping agent for bilirubin in the intestine, thereby preventing back-diffusion across the intestinal wall. In this study, we tested whether feeding calcium phosphate leads to enhanced excretion of unconjugated bilirubin in Gunn rats. When a purified control diet was substituted by a high calcium phosphate diet, a decrease in bilirubin levels of 30% to 50% in male Gunn rats and of 23% in female rats was observed. The fecal output of bilirubin was more than doubled in Gunn rats in the first 3 days after the normal diet had been replaced by the high calcium-phosphate diet. The biological half-life of 3 H-labeled bilirubin in blood was 89.8 +/- 17.2 hours in rats fed the purified control diet and 50.9 +/- 1.4 hours in rats fed the high calcium phosphate diet (P = .004). After 30 weeks, plasma bilirubin levels were still significantly lower in Gunn rats fed a high calcium phosphate diet. No differences were found in plasma concentrations of calcium, magnesium, phosphate, urea, and creatinine in both Gunn rats and Wistar rats on control or high calcium phosphate diets. This therapy might be useful in the management of Crigler-Najjar patients, for example, as an adjunct to phototherapy.
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Affiliation(s)
- C N Van Der Veere
- Department of Gastrointestinal and Liver Diseases, Academic Medical Center, Amsterdam, The Netherlands
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Montú M, Anger K, Bakker C. Larval development of the Chinese mitten crabEriocheir sinensis H. Milne-Edwards (Decapoda: Grapsidae) reared in the laboratory. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf02367153] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bosma PJ, Chowdhury JR, Bakker C, Gantla S, de Boer A, Oostra BA, Lindhout D, Tytgat GN, Jansen PL, Oude Elferink RP. The genetic basis of the reduced expression of bilirubin UDP-glucuronosyltransferase 1 in Gilbert's syndrome. N Engl J Med 1995; 333:1171-5. [PMID: 7565971 DOI: 10.1056/nejm199511023331802] [Citation(s) in RCA: 1094] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND People with Gilbert's syndrome have mild, chronic unconjugated hyperbilirubinemia in the absence of liver disease or overt hemolysis. Hepatic glucuronidating activity, essential for efficient biliary excretion of bilirubin, is reduced to about 30 percent of normal. METHODS We sequenced the coding and promoter regions of the gene for bilirubin UDP-glucuronosyltransferase 1 (bilirubin/uridine diphosphoglucuronate-glucuronosyltransferase 1)--the only enzyme that contributes substantially to bilirubin glucuronidation--in 10 unrelated patients with Gilbert's syndrome, 16 members of a kindred with a history of Crigler-Najjar syndrome type II, and 55 normal subjects. RESULTS The coding region of the gene for the enzyme was normal in the 10 patients with Gilbert's syndrome. These patients were homozygous for two extra bases (TA) in the TATAA element of the 5' promoter region of the gene (A(TA)7TAA rather than the normal A(TA)6TAA). The presence of the longer TATAA element resulted in the reduced expression of a reporter gene, encoding firefly luciferase, in a human hepatoma cell line. The frequency of the abnormal allele was 40 percent among the normal subjects. The 3 men in the control group who were homozygous for the longer TATAA element had significantly higher serum bilirubin levels than the other 52 normal subjects (P = 0.009). Among the kindred with a history of Crigler-Najjar syndrome type II, only the six heterozygous carriers who had a longer TATAA element on the structurally normal allele had mild hyperbilirubinemia, characteristic of Gilbert's syndrome. CONCLUSIONS Reduced expression of bilirubin UDP-glucuronosyltransferase 1 due to an abnormality in the promoter region of the gene for this enzyme appears to be necessary for Gilbert's syndrome but not sufficient for the complete manifestation of the syndrome.
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Affiliation(s)
- P J Bosma
- Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands
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Roelofsen H, Schoemaker B, Bakker C, Ottenhoff R, Jansen PL, Elferink RP. Impaired hepatocanalicular organic anion transport in endotoxemic rats. Am J Physiol 1995; 269:G427-34. [PMID: 7573454 DOI: 10.1152/ajpgi.1995.269.3.g427] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To investigate the mechanism of sepsis-associated hyperbilirubinemia we have studied hepatocanalicular transport of organic anions in a rat model of endotoxemia. Rats were injected intravenously with lipopolysaccharides (LPS), and at different times after injection, canalicular transport of 2,4-dinitrophenyl-S-glutathione (GS-DNP), as a model organic anion, was measured in perfused livers and isolated hepatocytes. In isolated liver perfusion experiments the initial biliary GS-DNP secretion rate was found to be significantly decreased 18 h after injection with 2 mg/kg LPS. In isolated hepatocytes from these rats, GS-DNP efflux rate was also significantly decreased (193.0 +/- 67 and 448.3 +/- 53 nmol.min-1.g dry wt-1 in endotoxemic and normal hepatocytes, respectively). Inhibition of GS-DNP effluxin isolated endotoxemic hepatocytes was dose dependent and reached a maximum with 0.25 mg/kg LPS. Inhibition was maximal at 12 h after LPS injection. Transport activity gradually returned to normal in 4-5 days after endotoxemia was induced. Dexamethasone pretreatment partially reversed the inhibition of GS-DNP transport in isolated endotoxemic hepatocytes. The phorbol ester phorbol 12-myristate 13-acetate increased GS-DNP efflux by 73 +/- 16 and 24 +/- 8% in endotoxemic and control hepatocytes, respectively, but could not restore the transport activity of endotoxemic hepatocytes to control levels. These results show that canalicular organic anion transport is decreased in the endotoxemic liver; this may play a role in the frequently observed hyperbilirubinemia during sepsis.
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Affiliation(s)
- H Roelofsen
- Division of Gastrointestinal and Liver Diseases, Academic Medical Center, Amsterdam, The Netherlands
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Bakker C, Rutten M, van Santen-Hoeufft M, Bolwijn P, van Doorslaer E, Bennett K, van der Linden S. Patient utilities in fibromyalgia and the association with other outcome measures. J Rheumatol 1995; 22:1536-43. [PMID: 7473480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To compare in patients with fibromyalgia (FM) utilities derived by rating scale and standard gamble methods; to gain insight into construct validity by relating utility values to other outcome measures; to assess the sensitivity to change of utilities. METHODS A total of 73 patients with FM were randomized into one of 3 groups: low impact fitness training, biofeedback, or controls. At baseline and after 6 mo the Maastricht Utility Measurement Questionnaire was applied. By means of both the rating scale and standard gamble method patients were asked to value their own health status. Construct validity of patient utility measurements was evaluated by Spearman correlation and multiple regression of baseline values with pain, stiffness, patient's global assessment, Sickness Impact Profile (SIP), modified Health Assessment Questionnaire and Arthritis Impact Measurement Scale (AIMS). Sensitivity to change was assessed against changes in these outcomes. RESULTS Rating scale utilities correlated significantly (p < 0.05) with patient's global assessment (rs = 0.53), pain (rs = -0.47), SIP (rs = -0.43), and with 9 of 11 dimensions of the AIMS (rs ranging from 0.23 to 0.62). Standard gamble utilities correlated significantly with mobility, pain, and arthritis impact of the AIMS scale (rs from 0.22 to 0.36) and with pain by visual analog scale (rs = -0.24) and patient's global assessment (rs = 0.32). Multiple regression analysis showed that patient's global assessment explained 41% (rating scale) and 10% (standard gamble) of total variance in baseline utilities. Also, 16% of the variance in change in rating scale utility values was explained by changes in patient's global assessment. In contrast, variance of changes in standard gamble utility values was not explained significantly by changes in other disease outcomes. CONCLUSION Rating scale utilities correlated more strongly with disease outcome measures than standard gamble utilities. Also, construct validity for the rating scale was better than for the standard gamble. In FM, utility measurement is sensitive to the method chosen to elicit patient priorities.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Bakker C, van der Linden S, van Santen-Hoeufft M, Bolwijn P, Hidding A. Problem elicitation to assess patient priorities in ankylosing spondylitis and fibromyalgia. J Rheumatol 1995; 22:1304-10. [PMID: 7562763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To elicit patient priorities as outcome measures in ankylosing spondylitis (AS) and fibromyalgia (FM); to relate these measures to other outcomes; to assess construct validity and sensitivity to change of the problem elicitation technique (PET) questionnaire. METHODS One hundred thirty-four patients with AS were randomly allocated to weekly sessions of group physical therapy or daily exercises at home, whereas 73 patients with FM were randomized into one of 3 groups (low impact fitness, biofeedback, controls). The PET questionnaire was applied by trained interviewers at baseline and at 6 (FM) and 9 (AS) month followup. A PET score was calculated at each assessment. Construct validity of the PET was assessed by correlation and multiple regression of baseline values with other disease outcomes (pain, stiffness, patient's global assessment, Sickness Impact Profile (SIP), Health Assessment Questionnaire (HAQ), Arthritis Impact Measurement Scale (AIMS), patient utilities). Sensitivity to change of PET was assessed against changes in these outcomes and by comparing the efficiency of the PET with other outcomes. RESULTS Patients with FM identified more problems (mean 6.8) than patients with AS (mean 4.4). Moreover, more patients with AS than with FM were unable to identify any problem at baseline (10% compared to 1%). The PET score improved from 14.9 to 11.3 (p = 0.0001) in patients with AS but did not change from 21.8 to 21.1 (p = 0.24) in patients with FM. Construct validity testing of the PET score showed statistically significant (p < 0.05) correlations with AIMS, utilities, SIP, HAQ, pain, stiffness, and patient's global health in both groups of patients (r varying from 0.22 to 0.66). By multiple regression pain explained 29% of the variance in PET scores among patients with AS. In FM patient global assessment accounted for 39% of total variance of PET scores, whereas pain explained another 15%. Changes in PET scores correlated significantly (p < 0.05) with changes in AIMS, utilities, pain, stiffness, and patient global health in both AS and FM (r varying from 0.22 to 0.51). Some 6% of the variance in changes in PET scores was explained by changes in pain in patients with AS and 35% by changes in pain and subjective health in patients with FM. Assessment of sensitivity to change revealed that efficiency of the PET score was 0.6 in patients with AS and 0.09 in those with FM. Compared to other outcomes this was reasonable in patients with AS but low in those with FM. CONCLUSION Obtaining patient priorities was generally feasible. In both groups of patients construct validity of the PET questionnaire was satisfactory. The PET was much more sensitive to change in patients with AS than in patients with FM.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Bakker C, van der Linden S. Health related utility measurement: an introduction. J Rheumatol 1995; 22:1197-9. [PMID: 7674256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Utility measures of health related quality of life are preference values that patients attach to their overall health status. In clinical trials, utility measures summarize both positive and negative effects of an intervention into one value between 0 (equal to death) and 1 (equal to perfect health). These measures allow for comparison of patient outcomes of different diseases, and for comparison between various health care interventions. There are 2 different approaches to utility measurement. The first is to classify patients into categories based on their responses to questions about their functional status, as for instance the Quality of Well-Being Questionnaire and the European Quality of Life Measure (EUROQOL). The 2nd approach is to ask patients to assign a single rating to their overall health by means of rating scale, standard gamble, time tradeoff, or willingness to pay. The Quality Adjusted Life Year (QALY) outcome measure includes both effects in terms of quality of quantity of life. Utilities are used as weights to adjust life years for the quality of life in order to calculate QALY. Both QALY and utilities are useful in decision making regarding appropriate procedures for groups of patients.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Abstract
Only two of the fragile sites found in humans (FRAXA and FRAXE) have been associated with a clinical phenotype. In mentally retarded individuals with cytogenetic expression of FRAXA a CGG repeat in the FMR1 gene is amplified. Fragile sites are found in many animals species. We have analyzed the FRAXA region containing the CGG repeat in several different species by PCR amplification. In most mammals this region could be amplified; the number of copies of the repeat is deduced.
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Affiliation(s)
- W Deelen
- Department of Clinical Genetics, Erasmus University, Rotterdam, The Netherlands
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Bosma PJ, Seppen J, Goldhoorn B, Bakker C, Oude Elferink RP, Chowdhury JR, Chowdhury NR, Jansen PL. Bilirubin UDP-glucuronosyltransferase 1 is the only relevant bilirubin glucuronidating isoform in man. J Biol Chem 1994; 269:17960-4. [PMID: 8027054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Crigler-Najjar syndrome type I (CN-I) is caused by an inherited absence of UDP-glucuronosyltransferase activity toward bilirubin (B-UGT), resulting in severe non-hemolytic unconjugated hyperbilirubinemia. Based on the expression of cDNAs in COS cells, two UGT isoforms in human liver, B-UGT1 and B-UGT2, have been reported to catalyze bilirubin glucuronidation. These isoforms, which are derived from a single gene, ugt1, have identical carboxyl-terminal domains that are encoded by four consecutive exons shared by both isoforms. A critical lesion in any of these common exons should inactivate both B-UGT isoforms, giving rise to CN-I. The amino-terminal domains of the B-UGT isoforms are unique, each being encoded by a different 5' exon. If both B-UGT isoforms contribute significantly to bilirubin glucuronidation, a mutation in one of these unique 5' exons should affect a single isoform, while the other isoforms should provide residual B-UGT activity. However, in two patients with CN-I, we found a mutation only in the unique exon of B-UGT1, the other exons being normal. To clarify this apparent paradox, we expressed the cDNA for each B-UGT isoform in COS cells and determined the specific B-UGT activity. These studies show that only B-UGT1 has quantitatively significant catalytic activity. Furthermore, we show that the mutation in B-UGT1 observed in each of the two CN-I patients inactivates B-UGT1. Together, the results indicate that B-UGT1 is the only physiologically relevant isoform in bilirubin glucuronidation.
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Affiliation(s)
- P J Bosma
- Division of Gastroenterology, Academic Medical Centre, Amsterdam, The Netherlands
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Bosma P, Seppen J, Goldhoorn B, Bakker C, Oude Elferink R, Chowdhury J, Chowdhury N, Jansen P. Bilirubin UDP-glucuronosyltransferase 1 is the only relevant bilirubin glucuronidating isoform in man. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32403-1] [Citation(s) in RCA: 312] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bakker C, Rutten-van Mölken M, Hidding A, van Doorslaer E, Bennett K, van der Linden S. Patient utilities in ankylosing spondylitis and the association with other outcome measures. J Rheumatol 1994; 21:1298-304. [PMID: 7966073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To compare in patients with ankylosing spondylitis (AS) utilities derived by rating scale and standard gamble method, to relate these values to other outcome measures, and to assess the sensitivity to change of utilities relative to changes in other outcomes. METHODS Patients with AS were randomly allocated to either weekly sessions of supervised group physical therapy for a period of 9 months or daily exercises at home. Analysis was restricted to the 59 patients who completed the Maastricht Utility Measurement Questionnaire (MUMQ) at baseline and after 9 months' followup and who were seen by the same interviewer. Reliability was assessed by intraclass correlation coefficient and change scores for marker states of disease. Construct validity was evaluated by correlation and multiple regression of baseline values with a variety of disease outcomes (pain and stiffness, patient's and physician's global assessment, Sickness Impact Profile, Health Assessment Questionnaire for the Spondyloarthropathies, Arthritis Impact Measurement Scale, functional, articular, and enthesis indices and spinal mobility measures). Sensitivity to change was assessed against changes in these outcome measures at followup. RESULTS The test-retest intraclass correlation coefficients for patient utilities were 0.95 (rating scale) and 0.79 (standard gamble), and for the marker state of mild disease 0.70 (rating scale) and 0.77 (standard gamble). A multiple regression analysis with the baseline rating scale or standard gamble utilities as dependent variable showed that patient's global assessment explained 59 and 11% of the total variance respectively. By multiple regression analysis 10% of the variance of change in rating scale utilities was explained by changes of patient's global assessment. In contrast, variance in change in standard gamble utilities was not explained by changes in other disease outcomes. CONCLUSION Findings obtained by rating scale and standard gamble differ considerably. Standard gamble utilities seem to address different aspects of health status than do rating scale utilities and more traditional outcomes. Utility measurement is sensitive to the method chosen to elicit patient well being.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Bakker C, Rutten M, van Doorslaer E, Bennett K, van der Linden S. Feasibility of utility assessment by rating scale and standard gamble in patients with ankylosing spondylitis or fibromyalgia. J Rheumatol Suppl 1994; 21:269-74. [PMID: 8182636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To assess the feasibility of utility measurement in patients with ankylosing spondylitis (AS) or fibromyalgia (FMS). Patient derived utilities provide overall estimates of the impact of a disease on patient well being. METHODS The Maastricht Utility Measurement Questionnaire was applied cross sectionally to 57 patients with AS and 86 outpatients with FMS. By means of rating scale and standard gamble techniques, patients were asked to value their own health state. RESULTS All 143 patients completed the interview. Patients with AS valued their personal health state on the rating scale (0-100) considerably higher than patients with FMS (AS: 69 and FMS: 54). Standard gamble utility values (0-1), however, were about the same at a higher level (AS: 0.86 and FMS: 0.83). Four weeks test-retest reliability was examined in 15 patients with FMS. The intraclass correlation coefficient of the utility score for the patient's own health state was 0.56 for the rating scale and 0.66 for the standard gamble technique. CONCLUSION Feasibility of the Maastricht Utility Measurement Questionnaire was generally satisfactory in both patient groups. Utility values obtained by rating scale and standard gamble technique differed considerably. Our data support the view that utility measurement is sensitive to the method chosen to elicit patient well being.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Bakker C, Hidding A, van der Linden S, van Doorslaer E. Cost effectiveness of group physical therapy compared to individualized therapy for ankylosing spondylitis. A randomized controlled trial. J Rheumatol 1994; 21:264-8. [PMID: 8182635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Cost effectiveness analysis is helpful in setting priorities for funding of health care programs. We studied the cost effectiveness of supervised group physical therapy compared to unsupervised exercises at home in patients with ankylosing spondylitis (AS). METHODS A total of 144 patients with AS (modified New York criteria; mean age: 43 years) were randomized to unsupervised daily individualized exercises at home for 9 months or the same plus supervised group physical therapy (3 h weekly). At baseline and after 9 months we measured spinal mobility (thoracolumbar flexion and extension), fitness (maximum work capacity by ergometry), and patient's global assessment of change as measured on a visual analog scale. We used a questionnaire at baseline and a diary during the trial to measure AS related direct medical costs, such as doctor visits, paramedical treatment, medication and hospitalization. RESULTS The mean effects of group therapy and home exercises were, respectively, +0.9 cm (16%) and +0.5 cm (9%) for mobility, +7 watts (4%) and -2 watts (-1%) for fitness, and +1.7 (34%) and +0.3 (6%) for global health. These 3 differences were significant (p < 0.01 for mobility, p = 0.05 for fitness and p < 0.01 for global health). During the trial total medical costs decreased by an average of US $379 (44%) for group therapy, and by $257 (35%)/patient/year for the "home" group. Additional costs of group therapy were estimated at $531/patient/year ($177 for accommodation, $256 for therapist and $98 for materials). After the study 75% of the patients wanted to continue group physical therapy and were willing to pay for it. CONCLUSION Compared to therapy at home, additional benefits of group therapy cost $531/year, but reduced direct medical costs by $122/year. Hence, the beneficial effects of group therapy cost $409/patient with AS/year.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, The Netherlands
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Bakker C, Boers M, van der Linden S. Measures to assess ankylosing spondylitis: taxonomy, review and recommendations. J Rheumatol Suppl 1993; 20:1724-30. [PMID: 8295185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To critically review the current use and scope of measures to assess patients with ankylosing spondylitis (AS). METHODS Studies in English reported between January, 1986 and August, 1991 were identified both through computer searches of Index Medicus and manual searches of bibliographies. Only studies where assessment of patients with AS was a main topic were included. Information was extracted to classify measures as (1) physician assessed, (2) patient reported or (3) other assessments. RESULTS Physician assessed measures prevailed in 34 (79%) of the 43 studies included. Patient reported measures were mentioned in 29 (67%). Most physician assessed measures (67%) focussed on mobility, most patient reported measures (65%) focussed on discomfort. Single item global assessment by physician or patient, the most generic measure, was reported in 7 (16%) and in 17 (40%) studies, respectively. One study reported a measure which specifically addressed the patient's priorities regarding treatment risks. Other measures were reported in 22 (51%) studies, i.e., laboratory tests in all 22, and additionally radiographs in 2, and various measures in 6 studies. Side effects (by reports or otherwise) were noted in 26 (60%) studies. CONCLUSION Current assessment in AS incompletely encompasses the spectrum of relevant health status outcomes. Specifically, more attention should be paid to the patient's point of view.
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Affiliation(s)
- C Bakker
- Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands
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Bakker C, Pasmans S, Verhagen C, Van Haren M, Van der Gaag R, Hoekzema R. Characterization of soluble protein BCP 11/24 from bovine corneal epithelium, different from the principal soluble protein BCP 54. Exp Eye Res 1992; 54:201-9. [PMID: 1559549 DOI: 10.1016/s0014-4835(05)80209-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The water-soluble fraction of bovine corneal epithelium was analysed by polyacrylamide gel electrophoresis in the presence of SDS (SDS-PAGE). Next to the principal soluble protein BCP 54, which has recently been identified as a corneal aldehyde dehydrogenase (ALDH), another abundant protein was observed, which we have denoted BCP 11/24, due to its estimated molecular weight of 11 kDa in SDS-PAGE and 24 kDa in high performance gel filtration under non-denaturing conditions. This protein was isolated and characterized by biochemical and immunochemical techniques. The isolation of BCP 11/24 was initially hampered by its tendency to bind non-covalently to BCP 54. BCP 11/24 behaves identically in reduced and unreduced SDS-PAGE and is probably not a glycoprotein. Isoelectric focusing indicated microheterogeneity of BCP 11/24, yielding bands with isoelectric points of 6.1, 5.9, 5.7 and 5.6. A rabbit antiserum directed against BCP 11/24, that did not recognize BCP 54, demonstrated that the distribution of BCP 11/24 in different ocular tissues as well as its light microscopic localization in corneal epithelium is strikingly similar to that of BCP 54. Together with its tendency to interact with BCP 54 in vitro, this suggests the possibility that BCP 11/24 is associated with BCP 54 in vivo, fulfilling a function which may be related to the activity of BCP 54 as a corneal ALDH. In contrast with BCP 54, however, BCP 11/24 was not detectable in corneal endothelium. The antiserum did not detect any immunologically related molecules in corneal epithelium extracts of sheep, human or rat origin, indicating that BCP 11/24 is probably not as highly conserved as BCP 54.
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Affiliation(s)
- C Bakker
- Department of Ophthalmo-Immunology, The Netherlands Ophthalmic Research Institute, Amsterdam
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Aerts R, Berendse F, Klerk NM, Bakker C. Root production and root turnover in two dominant species of wet heathlands. Oecologia 1989; 81:374-378. [PMID: 28311192 DOI: 10.1007/bf00377087] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/1989] [Accepted: 06/01/1989] [Indexed: 11/30/2022]
Abstract
Root biomass production, root length production and root turnover of Erica tetralix and Molinia caerulea were estimated by sequential core sampling and by observations in permanent minirhizotrons in the field. Root biomass production, estimated by core sampling, was 370 (Erica) and 1080 (Molinia) g m-2 yr-1. This was for both species equal to aboveground production. Assuming steady-state conditions for the root system, root biomass turnover rates (yr-1), estimated by core sampling, were 1.72 (Erica) and 1.27 (Molinia). Root length production of both species, estimated by minirhizotron observations, varied significantly with observation depth. Root length turnover rate (yr-1) of both species did not vary significantly with observation depth and averaged 0.92 in Erica and 2.28 in Molinia. Reasons are given for the discrepancy between the results of the two types of turnover measurements. The data suggest that the replacement of Erica by Molinia in a wet heathland, which occurs when nutrient availability increases, leads to an increased flow of carbon and nutrients into the soil-system. Therefore, there may be a positive feedback between dominance of Molinia and nutrient availability.
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Affiliation(s)
- R Aerts
- Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, NL-3512 PN, Utrecht, The Netherlands
| | - F Berendse
- Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, NL-3512 PN, Utrecht, The Netherlands
| | - N M Klerk
- Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, NL-3512 PN, Utrecht, The Netherlands
| | - C Bakker
- Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, NL-3512 PN, Utrecht, The Netherlands
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Van Rijswijk P, Bakker C, Vink M. Daily fecundity of Temora longicornis (Copepoda calanoida) in the Oosterschelde estuary (SW Netherlands). ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0077-7579(89)90050-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ochs HR, Greenblatt DJ, Eichelkraut W, Bakker C, Göbel R, Hahn N. Hepatic vs. gastrointestinal presystemic extraction of oral midazolam and flurazepam. J Pharmacol Exp Ther 1987; 243:852-6. [PMID: 3694534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
An experimental model was developed to elucidate the site of presystemic extraction of drugs with incomplete bioavailability due to high extraction after p.o. dosage. Domestic pigs received single i.v. or p.o. doses of midazolam (1 mg/kg) or flurazepam (2 mg/kg), two benzodiazepine derivatives with high presystemic extraction after p.o. dosage. Multiple blood samples were simultaneously drawn from the portal vein and from a systemic vein during 8 hr after dosage. After i.v. administration, both drugs had high systemic serum clearance, averaging 24 ml/min/kg. Area under the serum concentration curve (AUC) for systemic vs. portal sites was nearly identical for midazolam (769 vs. 737 ng/ml x hr); for flurazepam, systemic AUC exceeded portal AUC (1035 vs. 778 ng/ml x hr, P less than .01). After p.o. dosage, the systemic/portal AUC ratio averaged 0.15 for midazolam and 0.11 for flurazepam; for both drugs, portal AUC after p.o. dosage did not differ significantly from systemic AUC after i.v. administration. Thus, the extensive presystemic extraction of orally administered midazolam and flurazepam are mainly attributable to hepatic biotransformation rather than metabolism either within the gastrointestinal tract or during absorption into the portal circulation.
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Affiliation(s)
- H R Ochs
- Medizinische und Chirurgische Universitätskliniken, University of Bonn, Federal Republic of Germany
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Bakker C, De Vries I. Phytoplankton- and nutrient dynamics in saline lake grevelingen (SW Netherlands) under different hydrodynamical conditions in 1978–1980. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0077-7579(84)90002-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bakker C. [Activities for additional nursing personnel: contribution for discussion]. Tijdschr Ziekenverpl 1980; 33:479-81. [PMID: 6901371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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