13 research outputs found

    Optimized pharmacological control over the AAV-Gene-Switch vector for regulable gene therapy.

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    Gene therapy in its current design is an irreversible process. It cannot be stopped in case of unwanted side effects, nor can expression levels of therapeutics be adjusted to individual patient's needs. Thus, the Gene-Switch (GS) system for pharmacologically regulable neurotrophic factor expression was established for treatment of parkinsonian patients. Mifepristone, the synthetic steroid used to control transgene expression of the GS vector, is an approved clinical drug. However, pharmacokinetics and -dynamics of mifepristone vary considerably between different experimental animal species and depend on age and gender. In humans, but not in any other species, mifepristone binds to a high-affinity plasma carrier protein. We now demonstrate that the formulation of mifepristone can have robust impact on its ability to activate the GS system. Furthermore, we show that a pharmacological booster, ritonavir (Rtv), robustly enhances the pharmacological effect of mifepristone, and allows it to overcome gender- and species-specific pharmacokinetic and -dynamic issues. Most importantly, we demonstrate that the GS vector can be efficiently controlled by mifepristone in the presence of its human plasma carrier protein, α1-acid glycoprotein, in a "humanized" rat model. Thus, we have substantially improved the applicability of the GS vector toward therapeutic use in patients

    Polyglutamine-expanded ataxin-3: a target engagement marker for spinocerebellar ataxia type 3 in peripheral blood

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    Background: Spinocerebellar ataxia type 3 is a rare neurodegenerative disease caused by a CAG repeat expansion in the ataxin-3 gene. Although no curative therapy is yet available, preclinical gene-silencing approaches to reduce polyglutamine (polyQ) toxicity demonstrate promising results. In view of upcoming clinical trials, quantitative and easily accessible molecular markers are of critical importance as pharmacodynamic and particularly as target engagement markers. Objective: We aimed at developing an ultrasensitive immunoassay to measure specifically polyQ-expanded ataxin-3 in plasma and cerebrospinal fluid (CSF). Methods: Using the novel single molecule counting ataxin-3 immunoassay, we analyzed cross-sectional and longitudinal patient biomaterials. Results: Statistical analyses revealed a correlation with clinical parameters and a stability of polyQ-expanded ataxin-3 during conversion from the pre-ataxic to the ataxic phases. Conclusions: The novel immunoassay is able to quantify polyQ-expanded ataxin-3 in plasma and CSF, whereas ataxin-3 levels in plasma correlate with disease severity. Longitudinal analyses demonstrated a high stability of polyQ-expanded ataxin-3 over a short period. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder SocietyFunding agencies: This project is supported by the EU Joint Programme—Neurodegenerative Disease Research (JPND) through the following funding organizations under the aegis of JPND: Germany, Federal Ministry of Education and Research (BMBF; funding codes 01ED1602A/B); Netherlands, The Netherlands Organisation for Health Research and Development; Portugal, Foundation for Science and Technology (FCT, grant number JPCOFUND/0001/2015), and Regional Fund for Science and Technology of the Azores; and United Kingdom, Medical Research Council. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement number 643417. In addition, support has been received by the BIONIC project (number 733050822, which has been made possible by ZonMW as part of “Memorabel,” the research and innovation program for dementia, as part of the Dutch national “Deltaplan for Dementia”: zonmw.nl/dementiaresearch), the CAF[1]E project (the National Institutes of Health, USA, grant number 5R01NS104147-02), and a grant from the Selfridges Group Foundation (NR170024). The BIONIC project is a consortium of Radboudumc, LUMC, ADX Neurosciences, and Rhode Island University

    Involvement of dopamine D1 and D2 receptors in the nucleus accumbens core and shell in inhibitory response control

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    Rationale: Impaired inhibitory control over behavior is a key feature in various psychiatric disorders, and recent studies indicated an important role for dopamine D1 and D2 receptors and the nucleus accumbens (Acb) in this respect. Objective: The present experiments were designed to study the role of dopamine D1 and D2 receptors in the Acb in inhibitory response control. Methods: Rats were trained in a five-choice serial reaction time task and received bilateral infusions into the Acb core or shell of either SCH 23390 or eticlopride (representing selective dopamine D 1 and D2 receptor antagonists, respectively). Subsequently, the effects of systemic amphetamine on inhibitory response control were examined. Results: Eticlopride into either the Acb core or shell did not affect premature responding, a measure for inhibitory response control, but increased reaction time and errors of omission. In contrast, SCH 23390 into both regions reduced premature responding, slightly improved attentional performance in the core and increased errors of omission in the shell. Amphetamine robustly increased premature responding which was dose-dependently blocked by eticlopride in the Acb core and attenuated by eticlopride in the shell. In addition, amphetamine slightly decreased accuracy and reaction time, and these effects were inhibited by eticlopride in both regions. SCH 23390 infusion into the Acb core or shell did not alter amphetamine's effects. Conclusion: Our data provide evidence for the involvement of dopamine D1 and D2 receptors in the Acb core and shell in inhibitory response control and attentional performance

    Improved early identification of arthritis:evaluating the efficacy of Early Arthritis Recognition Clinics

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    <p>Objective Only 31% of Dutch rheumatoid arthritis (RA)-patients visit a rheumatologist within 12weeks after symptom onset; this is mainly due to delay at the level of the general practitioner (GP). In order to reduce delay of GPs in identifying early arthritis, we initiated an Early Arthritis Recognition Clinic (EARC).</p><p>Methods EARCs were initiated at the Leiden and Groningen University Medical Centers. At this EARC, patients filled in a questionnaire about their symptoms, followed by a short visit with only a full joint examination by an experienced rheumatologist. If arthritis was present the patient got an appointment the same week at the regular outpatient clinic. The main outcome parameter was the GP-delay; the secondary outcome parameter was the total delay. In both centres, patients included in early arthritis clinics that had arrived via regular referrals served as control group.</p><p>Results Four hundred patients visited the Leiden EARC and 212 patients the Groningen EARC. Arthritis was detected in 42% and 49% respectively. The median GP-delay for these arthritis patients was 2.0 (0.4-7.3) and 2.0 (0.4-10.0) weeks and the median total delay 8.6 (3.6-22.3) and 10.6 (3.1-30.8) weeks respectively. At these two clinics 59% and 51% of all arthritis patients and 65% and 53% of the patients that were subsequently diagnosed with undifferentiated arthritis or RA were seen within 12weeks after symptom onset. In the Leiden and Groningen control groups that arrived via regular referrals, only 32% and 38% were seen within 12weeks time.</p><p>Conclusions The EARC increased the early identification of arthritis and RA.</p>

    Reasons for medical help-seeking behaviour of patients with recent-onset arthralgia

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    <p>Objective Patient delay in seeking medical help may cause suboptimal use of the therapeutic window in rheumatoid arthritis. We aimed to assess the motivations and the urgency with which patients with arthralgia seek medical help.</p><p>Methods 612 patients with arthralgiavisiting two Dutch Early Arthritis Recognition Clinicswere studied. Patients filled out a questionnaire with questions on their symptoms and their reasons for seeking medical help. Comparisons were made for patients with short or prolonged patient delay, patients with and without arthritis, age and gender.</p><p>Results The median symptom duration was 4weeks. A prolonged delay in seeking help was associated with a gradual onset of symptoms (78%) and the perception that symptoms would not be serious or would go away (16% and 48%, respectively). Arthralgia patients who promptly sought medical help more often had an acute onset of symptoms and more frequently reported impairments at work or in daily functioning than patients who postponed seeking help (all p</p><p>Conclusions This large-scale study observed several reasons and symptom characteristics influencing the help-seeking behaviour of persons with arthralgia. These data can be helpful to define strategies aiming at early identification of arthritis.</p>

    Mechanism of Isoflavone Adsorption from Okara Extracts onto Food-Grade Resins

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    Okara is a byproduct of the soy milk industry containing valuable phytochemicals, called isoflavones, among other components (i.e., proteins, sugars, fibers, etc.). As a waste product, okara is an interesting source material for obtaining valuable chemicals, and knowledge of the behavior of such components in their complex matrix is a key step for design of a purification process. Six commercially available macroporous polymeric resins are investigated to measure and model the equilibrium properties of the adsorption of isoflavones, proteins, and total solids onto these resins. A new model is evaluated in which adsorption of isoflavones onto a protein layer is proposed describing the system isoflavones–resin XAD 4 better than a linear isotherm model. Parameters for both the linear model and the bilayer model are regressed and reported with their accuracy and correlated to the hydrophobicity of each of the isoflavones

    Dopamine Receptor D-1/D-5 Gene Expression in the Medial Prefrontal Cortex Predicts Impulsive Choice in Rats

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    A neuropsychological hallmark of attention deficit/hyperactivity disorder (ADHD) is the reduced ability to tolerate delay of reinforcement, leading to impulsive choice. Genetic association studies have implicated several genes involved in dopaminergic neurotransmission in ADHD. In this study, we investigated whether differences in the expression level of these dopamine-related genes of rats predict the individual level of impulsive choice. Among all frontostriatal brain regions tested, only in the medial prefrontal cortex (mPFC), we observed significant positive correlations between impulsive choice and transcript levels of the dopamine receptor D1, the dopamine receptor D5 and calcyon. Local mPFC infusions of the
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