Aims SCN5A mutations are associated with various cardiac phenotypes, including long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), and cardiac conduction disease (CCD). Certain mutations, such... Show moreAims SCN5A mutations are associated with various cardiac phenotypes, including long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), and cardiac conduction disease (CCD). Certain mutations, such as SCN5A-1795insD, lead to an overlap syndrome, with patients exhibiting both features of BrS/CCD [decreased sodium current (I-Na)] and LQT3 (increased late I-Na). The sodium channel blocker mexiletine may acutely decrease LQT3-associated late I-Na and chronically increase peak I-Na associated with SCN5A loss-of-function mutations. However, most studies have so far employed heterologous expression systems and high mexiletine concentrations. We here investigated the effects of a therapeutic dose of mexiletine on the mixed phenotype associated with the SCN5A-1795insD mutation in HEK293A cells and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Methods and results To assess only the chronic effects on trafficking, HEK293A cells transfected with wild-type (WT) SCN5A or SCN5A-1795insD were incubated for 48 h with 10 & mu;m mexiletine followed by wash-out, which resulted in an increased peak I-Na for both SCN5A-WT and SCN5A-1795insD and an increased late I-Na for SCN5A-1795insD. Acute re-exposure of HEK293A cells to 10 & mu;m mexiletine did not impact on peak I-Na but significantly decreased SCN5A-1795insD late I-Na. Chronic incubation of SCN5A-1795insD hiPSC-CMs with mexiletine followed by wash-out increased peak I-Na, action potential (AP) upstroke velocity, and AP duration. Acute re-exposure did not impact on peak I-Na or AP upstroke velocity, but significantly decreased AP duration. Conclusion These findings demonstrate for the first time the therapeutic benefit of mexiletine in a human cardiomyocyte model of SCN5A overlap syndrome. Show less
Gharbharan, A.; Jordans, C.; Zwaginga, L.; Papageorgiou, G.; Geloven, N. van; Wijngaarden, P. van; ... ; CoV-Early study grp 2023
Objectives: The potential benefit of convalescent plasma (CP) therapy for coronavirus disease 2019 (COVID-19) is highest when administered early after symptom onset. Our objective was to determine... Show moreObjectives: The potential benefit of convalescent plasma (CP) therapy for coronavirus disease 2019 (COVID-19) is highest when administered early after symptom onset. Our objective was to determine the effectiveness of CP therapy in improving the disease course of COVID-19 among high-risk outpatients. Methods: A multicentre, double-blind randomized trial was conducted comparing 300 mL of CP with non-CP. Patients were >= 50 years, were symptomatic for <8 days, had confirmed RT-PCR or antigen test result for COVID-19 and had at least one risk factor for severe COVID-19. The primary endpoint was the highest score on a 5-point ordinal scale ranging from fully recovered (score = 1) or not (score = 2) on day 7, over hospital admission (score = 3), intensive care unit admission (score = 4) and death (score = 5) in the 28 days following randomization. Secondary endpoints were hospital admission, symptom duration and viral RNA excretion. Results: After the enrolment of 421 patients and the transfusion in 416 patients, recruitment was dis-continued when the countrywide vaccination uptake in those aged >50 years was 80%. Patients had a median age of 60 years, symptoms for 5 days, and 207 of 416 patients received CP therapy. During the 28 day follow-up, 28 patients were hospitalized and two died. The OR for an improved disease severity score with CP was 0.86 (95% credible interval, 0.59-1.22). The OR was 0.58 (95% CI, 0.33-1.02) for patients with <5 days of symptoms. The hazard ratio for hospital admission was 0.61 (95% CI, 0.28-1.34). No difference was found in viral RNA excretion or in the duration of symptoms. Conclusions: In patients with early COVID-19, CP therapy did not improve the 5-point disease severity score. Arvind Gharbharan, Clin Microbiol Infect 2023;29:208 (c) 2022 The Authors. Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/). Show less
Every day Tuberculosis (TB) kills approximately three thousand people, a number that is on the rise due to the impact of the current COVID-19 pandemic on essential TB services. The causative agent... Show moreEvery day Tuberculosis (TB) kills approximately three thousand people, a number that is on the rise due to the impact of the current COVID-19 pandemic on essential TB services. The causative agent of TB, Mycobacterium tuberculosis (Mtb), is an ancient pathogen that through its evolution developed complex mechanisms to evade immune surveillance and acquired the ability to establish persistent infection in its hosts. To achieve TB eradication, the discovery of Mtb antigens that effectively correlate with the human response to infection, with the curative host response following TB treatment, and with natural as well as vaccine induced protection is critical. This thesis contributes to this ambitious aim through several findings. First, it uncovers multiple new in vivo expressed Mtb (IVE-TB) antigens by combining Mtb-transcriptomic data with advanced bioinformatics tools and medium throughput cytokine screening. Second, it deepens our understanding of the cellular and humoral immunity to Mtb antigens in latently Mtb infected donors (LTBIs) and TB patients as well as in animal models. Lastly, it demonstrates the feasibility of combining and integrating pre-clinical research of multiple mycobacterial diseases, which are endemic in the same areas and against which vaccines could induce cross-disease protection (i.e., TB and leprosy). Show less
This thesis examines silicon pore optics (SPO), a technology that exploits silicon wafers from the semiconductor industry to create extremely high quality X-ray optics, by studying its... Show moreThis thesis examines silicon pore optics (SPO), a technology that exploits silicon wafers from the semiconductor industry to create extremely high quality X-ray optics, by studying its manufacturing process, applications, and prospects. SPO technology has become very mature thanks to the continuous development efforts to prepare for the industrial production of Athena, the largest space-borne X-ray telescope yet to be launched. In effect, SPO is also a versatile technology that can be further developed for a wide range of applications, including radiation therapy. Show less
Integrins mediate adhesive interactions between cells and their environment, including neighboring cells and extracellular matrix (ECM). These heterodimeric transmembrane receptors bind... Show moreIntegrins mediate adhesive interactions between cells and their environment, including neighboring cells and extracellular matrix (ECM). These heterodimeric transmembrane receptors bind extracellular ligands with their globular head domains and connect to the cytoskeleton through multi-protein interactions at their cytoplasmic tails. Integrin containing cell-matrix adhesions are dynamic force-responsive protein complexes that allow bidirectional mechanical coupling of cells with their environment. This allows cells to sense and modulate tissue mechanics and regulates intracellular signaling impacting on cell faith, survival, proliferation, and differentiation programs. Dysregulation of these functions has been extensively reported in cancer and associated with tumor growth, invasion, angiogenesis, metastasis, and therapy resistance. This central role in multiple hallmarks of cancer and their localization on the cell surface makes integrins attractive targets for cancer therapy. However, despite a wealth of highly encouraging preclinical data, targeting integrin adhesion complexes in clinical trials has thus far failed to meet expectations. Contributing factors to therapeutic failure are 1) variable integrin expression, 2) redundancy in integrin function, 3) distinct roles of integrins at various disease stages, and 4) sequestering of therapeutics by integrin-containing tumor-derived extracellular vesicles. Despite disappointing clinical results, new promising approaches are being investigated that highlight the potential of integrins as targets or prognostic biomarkers. Improvement of therapeutic delivery at the tumor site via integrin binding ligands is emerging as another successful approach that may enhance both efficacy and safety of conventional therapeutics. In this review we provide an overview of recent encouraging preclinical findings, we discuss the apparent disagreement between preclinical and clinical results, and we consider new opportunities to exploit the potential of integrin adhesion complexes as targets for cancer therapy. Show less
Gyrate atrophy of the choroid and retina (GACR) is a rare inborn error of amino acid metabolism caused by bi-allelic variations in OAT. GACR is characterised by vision decline in early life... Show moreGyrate atrophy of the choroid and retina (GACR) is a rare inborn error of amino acid metabolism caused by bi-allelic variations in OAT. GACR is characterised by vision decline in early life eventually leading to complete blindness, and high plasma ornithine levels. There is no curative treatment for GACR, although several therapeutic modalities aim to slow progression of the disease by targeting different steps within the ornithine pathway. No international treatment protocol is available. We systematically collected all international literature on therapeutic interventions in GACR to provide an overview of published treatment effects. Methods: Following the PRISMA guidelines, we conducted a systematic review of the English literature until December 22nd 2020. PubMed and Embase databases were searched for studies related to therapeutic interventions in patients with GACR. Results: A total of 33 studies (n = 107 patients) met the inclusion criteria. Most studies were designed as case reports (n = 27) or case series (n = 4). No randomised controlled trials or large cohort studies were found. Treatments applied were protein-restricted diets, pyridoxine supplementation, creatine or creatine precursor supplementation, L-lysine supplementation, and proline supplementation. Protein-restricted diets lowered ornithine levels ranging from 16.0-91.2%. Pyridoxine responsiveness was reported in 30% of included mutations. Lysine supplementation decreased ornithine levels with 21-34%. Quality assessment showed low to moderate quality of the articles. Conclusions: Based primarily on case reports ornithine levels can be reduced by using a protein restricted diet, pyridoxine supplementation (variation-dependent) and/or lysine supplementation. The lack of pre-defined clinical outcome measures and structural follow-up in all included studies impeded conclusions on clinical effectiveness. Future research should be aimed at 1) Unravelling the OAT biochemical pathway to identify other possible pathologic metabolites besides ornithine, 2) Pre-defining GACR specific clinical outcome measures, and 3) Establishing an international historical cohort. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). Show less
Esch, B. van; Zaag-loonen, H. van der; Bruintjes, T.; Benthem, P.P. van 2021
Background: Meniere's disease is characterized by recurrent episodes of vertigo, hearing loss, and tinnitus, often with a feeling of fullness in the ear. Although betahistine is thought to be... Show moreBackground: Meniere's disease is characterized by recurrent episodes of vertigo, hearing loss, and tinnitus, often with a feeling of fullness in the ear. Although betahistine is thought to be specifically effective for Meniere's disease, no evidence for a benefit from the use of betahistine exists, despite its widespread use. Reassessment of the effect of betahistine for Meniere's disease is now warranted. Search Methods: We searched for randomized controlled trials (RCTs) in the Central Register of Controlled Trials (CENTRAL), Ovid Medline, Ovid Embase, CINAHL, Web of Science, Clinicaltrials.gov, ICTRP, and additional sources for published and unpublished trials, in which betahistine was compared to placebo. Data Collection and Analysis: Our outcomes involved vertigo, significant adverse effect (upper gastrointestinal discomfort), hearing loss, tinnitus, aural fullness, other adverse effects, and disease-specific health-related quality of life. We used GRADE to assess the quality of the evidence. Main Results: We included 10 studies: 5 studies used a crossover design and the remaining 5 were parallel-group RCTs. One study with a low risk of bias found no significant difference between the betahistine groups and placebo with respect to vertigo after a long-term follow-up period. No significant difference in the incidence of upper gastrointestinal discomfort was found in 2 studies (low-certainty evidence). No differences in hearing loss, tinnitus, or well-being and disease-specific health-related quality of life were found (low- to very low-certainty of evidence). Data on aural fullness could not be extracted. No significant difference between the betahistine and the placebo groups (low-certainty evidence) could be demonstrated in the other adverse effect outcome with respect to dull headache. The pooled risk ratio for other adverse effect in the long term demonstrated a lower risk in favor of placebo over betahistine. Conclusions: High-quality studies evaluating the effect of betahistine on patients with Meniere's disease are lacking. However, one study with low risk of bias found no evidence of a difference in the effect of betahistine on the primary outcome, vertigo, in patients with Meniere's disease when compared to placebo. The main focus of future research should be on the use of comparable outcome measures by means of patient-reported outcome measures. Show less
Brugts, J.J.; Veenis, J.F.; Radhoe, S.P.; Linssen, G.C.M.; Gent, M. van; Borleffs, C.J.W.; ... ; Boer, R.A. de 2019
Background Assessing haemodynamic congestion based on filling pressures instead of clinical congestion can be a way to further improve quality of life (QoL) and clinical outcome by intervening... Show moreBackground Assessing haemodynamic congestion based on filling pressures instead of clinical congestion can be a way to further improve quality of life (QoL) and clinical outcome by intervening before symptoms or weight gain occur in heart failure (HF) patients. The clinical efficacy of remote monitoring of pulmonary artery (PA) pressures (CardioMEMS; Abbott Inc., Atlanta, GA, USA) has been demonstrated in the USA. Currently, the PA sensor is not reimbursed in the European Union as its benefit when applied in addition to standard HF care is unknown in Western European countries, including the Netherlands. Aims To demonstrate the efficacy and cost-effectiveness of haemodynamic PA monitoring in addition to contemporary standard HF care in a high-quality Western European health care system. Methods The current study is a prospective, multi-centre, randomised clinical trial in 340 patients with chronic HF (New York Heart Association functional class III) randomised to HF care including remote monitoring with the CardioMEMS PA sensor or standard HF care alone. Eligible patients have at least one hospitalisation for HF in 12 months before enrolment and will be randomised in a 1:1 ratio. Minimum follow-up will be 1 year. The primary endpoint is the change in QoL as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ). Secondary endpoints are the number of HF hospital admissions and changes in health status assessed by EQ-5D-5L questionnaire including health care utilisation and formal cost-effectiveness analysis. Conclusion The MONITOR HF trial will evaluate the efficacy and cost-effectiveness of haemodynamic monitoring by CardioMEMS in addition to standard HF care in patients with chronic HF. Clinical Trial Registration number NTR7672. Show less
This thesis investigates Nietzsche's reception of Stoicism, and whether there is evidence for Stoicism influencing Nietzsche's conception of amor fati. Although secondary literature has made it... Show moreThis thesis investigates Nietzsche's reception of Stoicism, and whether there is evidence for Stoicism influencing Nietzsche's conception of amor fati. Although secondary literature has made it seem plausible that amor fati carries traces of Stoicism, pointing to the conceptual parallels between the love of fate and the Stoic therapy of a life ‘in accordance with nature’, this historical study shows that this claim is unlikely. In the first and last chapters a thorough textual analysis is presented of amor fati, showing that the concept undergoes a significant development from 1881/1882 to 1888. The amor fati of 1881/1882 should be situated in the context of Nietzsche's growing interest in physiology, I claim. The middle chapters uncover Nietzsche's engagements with Stoicism, based on a study of all explicit (and implicit) references to Stoicism. I conclude that Nietzsche's focus is restricted mostly to the context of the scientific quest for knowledge, thereby putting in perspective the assumption that Nietzsche's interest is mainly therapeutic. Although Nietzsche seems sympathetic to a Stoic attitude in 1870, he unequivocally rejects it in 1881/1882, in the same Book of Die fröhliche Wissenschaft in which, not coincidentally, amor fati for the first time occurs in the published works. Show less
The aim of this thesis was to work towards pre-clinical proof-of-concept for NOTCH3 cysteine corrective exon skipping as a rational therapeutic approach for CADASIL. To address all aspects required... Show moreThe aim of this thesis was to work towards pre-clinical proof-of-concept for NOTCH3 cysteine corrective exon skipping as a rational therapeutic approach for CADASIL. To address all aspects required for therapeutic development, the work performed for this thesis included not only in vitro testing of NOTCH3 exon skipping in CADASIL patient derived vascular smooth muscle cells and studies into the function of the cysteine corrected proteins, but also the generation of a relevant humanized in vivo model, pre-clinical biomarker development, and studies defining prevalence, spectrum and characteristics of NOTCH3 mutations worldwide. Show less
Venous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the... Show moreVenous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the diagnostic management and therapy of recurrent venous thromboembolism still have limitations. This thesis discusses a new imaging technique for recurrent deep venous thrombosis and the duration of treatment after a recurrent venous thromboembolism. It shows that Magnetic Resonance Direct Thrombus Imaging might be a potential diagnostic tool for the diagnostic management of recurrent venous thromboembolism. Furthermore the prognosis after a first deep vein thrombosis is discussed by means of recurrence and bleeding risks. Show less
Broek, E.C. van den; Oerlemans, S.; Nijziel, M.R.; Posthuma, E.F.M.; Coebergh, J.W.W.; Poll-Franse, L.V. van de 2015
The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the... Show moreThe main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency ablation of spinal and non-spinal osteoid osteomas are discussed. The possible causes of treatment failure and methods for the detection of treatment failure were also analysed with the purpose of optimizing patient selection and the radiofrequency procedures, and solving high risk parameters for failure of treatment. Chapter two discusses the clinical outcome of a large series of 97 patients with spinal and non-spinal osteoid osteomas treated by radiofrequency ablation. Chapter three describes the theoretical and technical background of radiofrequency ablation. The concept of the treatment zone as well as related safety issues are also discussed. In Chapter four the possible mechanisms causing treatment failure are discussed. The potential role of CT and MRI imaging in the detection of recurrent or residual osteoid osteoma is addressed in Chapter five. Finally the treatment outcome of a group of 25 patients with spinal osteoid osteoma treated by radiofrequency ablation is presented in Chapter 6. A general discussion is provided in Chapter 7. Show less
Duchenne muscular dystrophy (DMD) is a severe, lethal neuromuscular disorder caused by reading frame disrupting mutations (mostly deletions) in the dystrophin gene. This results in the complete... Show moreDuchenne muscular dystrophy (DMD) is a severe, lethal neuromuscular disorder caused by reading frame disrupting mutations (mostly deletions) in the dystrophin gene. This results in the complete absence of dystrophin and leads to the continuous loss of muscle fibers and fibrosis. As a consequence, DMD patients are wheelchair dependent before the age of 12 and often die in the third decade of the life (or earlier) due to respiratory- or heart failure. Deletions in the dystrophin gene that keep the reading frame intact allow the generation of internally deleted, partly functional dystrophins and are associated with the milder Becker muscular dystrophy (BMD). Becker patients often remain ambulant until later in life and have near normal life expectancies. Normal dystrophin consists of an N-terminal actin-binding domain, a central rod domain (containing 24 spectrin-like repeat units and 4 hinge regions) a cysteine-rich and a C-terminal domain. Dystrophin is thought to fulfill a bridge function between the cytoskeleton and the extracellular matrix, since the actin binding domain binds to cytoskeletal actin, while the C-terminal domain is involved with the transmembranal dystrophin glycoprotein complex (DGC) that is connected to the extracellular matrix via laminin 2. In DMD patients this bridge function is completely lost, since the C-terminal bridgehead is lacking due to a truncating mutation. In BMD patients on the other hand, an internal deletion results in a shorter, but still semi-functional bridge that contains both the N-terminal and C-terminal bridgeheads. As yet there is no clinically applicable therapy for DMD patients, despite extensive research for a variety of different approaches. Currently, one of the most promising strategies is the antisense-mediated reading frame restoration. The aim of this approach is to induce specific exon skipping to convert an out of frame DMD transcript into its nearest in frame BMD-like counterpart. This would allow the generation of an internally deleted but partly functional dystrophin and should convert DMD into a milder BMD phenotype. The skipping of a specific exon can be induced by antisense oligoribonucleotides (AONs), which are small synthetic RNAs. Upon binding of the AONs to the pre-mRNA the splicing machinery does not recognize the exon as such anymore, and as a result the targeted exon is spliced out with its flanking introns (i.e. the exon is "skipped"). The broad mutation spectrum found for DMD would require the skipping of a series of exons to restore the reading frame for several patients. Fortunately, designing efficient DMD specific AONs has proven relatively easy, and we can currently induce the specific skipping of 20 different exons in human control myotube cultures after PEI-mediated AON delivery (Chapter 2). This would restore the reading frame for over 40% of all DMD patients. The broad therapeutic applicability of this technique was confirmed in myotube cultures derived from 8 different patients (Chapter 3). For each patient skipping of the specific exons could be induced on RNA level and dystrophin synthesis was restored in over 75% of treated myotubes. Time course experiments revealed that dystrophin was detectable as early as 16 hours post transfection and increasing levels were found for up to 7 days. In addition, expression of DGC proteins was restored in treated myotube cultures, further confirming the functionality of the BMD-like dystrophins. Since a significant part of DMD patients carries a mutation that requires the skipping of two exons, we also tested the feasibility of double-exon skipping in two patients (Chapter 4). After treatment with a mix of the respective AONs, double exon skipping was detected on RNA level and dystrophin synthesis was restored for over 70% of treated myotube cultures for both patients. Furthermore, when we treated control myotubes with AONs targeting exons 45 and 51 we observed multi-exon skipping of exon 45 through 51. Multi-exon skipping not only increases the applicability of this technique, it also reduces the mutation specificity, since it allows for the generation of a BMD-like deletion that covers the majority of DMD mutations. The skipping of exon 45 through 51 would already be applicable to 15% of all patients and its feasibility was confirmed in myotubes derived from a patient carrying an exon 48-50 deletion. Subsequent experiments aiming at the skipping of a larger number of exons seem to indicate that the number of exons that can be skipped is limited due to hitherto unknown processes. Thus far we have used AONs containing 2'-O-methyl RNA with a full-length phosphorothioate backbone (2OMePS), which are cytotoxic at high concentrations. For future clinical applications the optimal AON induces high levels of specific exon skipping at low levels of cytotoxicity. We thus compared the efficacy and efficiency of our most efficient exon 46 2OMePS AON to those of a morpholino, a locked nucleic acid (LNA) and a peptide nucleic acid (PNA) AON (Chapter 5). Only the LNA induced higher levels of exon skipping than 2OMePS in patient and control myotube cultures. However, when we compared the sequence specificity of these analogues we observed that LNAs appear to be much less sequence specific than 2OMePS AON. Therefore, we conclude that 2OMePS currently seem the favorable compounds to establish clinical trials. To study exon skipping in vivo we injected PEI-coupled 2OMePS AONs specific for murine exon 46 into the gastrocnemius muscle of normal mice (Chapter 6). Relatively low levels of exon 46 skipping could be detected on RNA level and persisted for over four weeks post injection. Furthermore, we have previously engineered a mouse model that contains the entire human DMD gene (2.6 Mb) integrated into the murine genome (hDMD mouse). These transgenic mice uniquely allow for the preclinical testing of human-specific AONs in vivo. We have injected AONs targeting human exons 44, 46 and 49 into the musculus. gastrocnemicus of hDMD mice, and showed that the skipping of the human exons (but not the murine exons) was indeed specifically induced. Based on pre-clinical data obtained by our group and others, we are currently setting up a clinical trial aiming at local dystrophin restoration following intramuscular injections of exon 46 and 51 specific AONs. For future application, however, we aim at systemic delivery of AONs. Therefore, we are currently investigating delivery methods that will allow systemic delivery of AONs. Show less
