55 research outputs found

    Aerobic exercise in children with oxidative phosphorylation defects

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    Fatigue and exercise intolerance are symptoms in children with metabolic myopathy. Frequently this is combined with muscle pain in children with mitochondrial myopathy. Offering therapeutic advice remains challenging in this patient group. Here we describe five children above the age of four years, with normal intelligence, myopathy, exercise intolerance, motor developmental delay, and fatigue, who were diagnosed with a mitochondrial dysfunction. Based on the positive experience of condition training in adults with mitochondrial disease and inactivity, aerobic exercise training was advised for all the children. Because of the lack of clear protocols for individualized mitochondrial myopathies, regular training was initiated. The Movement Assessment Battery of Children, the Jamar dynamometer for grip force, and the Bruce protocol treadmill test were applied for evaluation. No patient showed significant disease progression on a weekly scheme of strength training or on aerobic training during periods varying between 6 and 18 months. Only one out of the five patients has shown an improvement after a period of structured, aerobic training, demonstrating good compliance and motivation over the course of 18 months. Some patients developed severe muscle pain after explosive exercise. Even in a relatively homogenous, intelligent group of patients and motivated parents, we could not reach full compliance. With our case studies, we would like to draw attention to the importance and pitfalls of movement therapy in children with mitochondrial disease

    Robust brain-computer interfaces

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    A brain-computer interface (BCI) enables direct communication from the brain to devices, bypassing the traditional pathway of peripheral nerves and muscles. Current BCIs aimed at patients require that the user invests weeks, or even months, to learn the skill to intentionally modify their brain signals. This can be reduced to a calibration session of about half an hour per session if machine learning (ML) methods are used. The laborious recalibration is still needed due to inter-session differences in the statistical properties of the electroencephalography (EEG) signal. Further, the natural variability in spontaneous EEG violates basic assumptions made by the ML methods used to train the BCI classifier, and causes the classification accuracy to fluctuate unpredictably. These fluctuations make the current generation of BCIs unreliable. In this dissertation,we will investigate the nature of these variations in the EEG distributions, and introduce two new, complementary methods to overcome these two key issues. To confirm the problem of non-stationary brain signals, we first show that BCIs based on commonly used signal features are sensitive to changes in the mental state of the user. We proceed by describing a method aimed at removing these changes in signal feature distributions. We have devised a method that uses a second-order baseline (SOB) to specifically isolate these relative changes in neuronal firing synchrony. To the best of our knowledge this is the first BCI classifier that works on out-of-sample subjects without any loss of performance. Still, the assumption made by ML methods that the training data consists of samples that are independent and identically distributed (iid) is violated, because EEG samples nearby in time are highly correlated. Therefore we derived a generalization of the well-known support vector machine (SVM) classifier, that takes the resulting chronological structure of classification errors into account. Both on artificial data and real BCI data, overfitting is reduced with this dependent samples support vector machine (dSVM), leading to BCIs with an increased information throughput

    Predictors of Nonseroconversion to SARS-CoV-2 Vaccination in Kidney Transplant Recipients

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    Kidney transplant recipients (KTRs) are still at risk of severe COVID-19 disease after SARS‑CoV‑2 vaccination, especially when they have limited antibody formation. Our aim was to understand the factors that may limit their humoral response. METHODS. Our data are derived from KTRs who were enrolled in the Dutch Renal Patients COVID-19 Vaccination consortium, using a discovery cohort and 2 external validation cohorts. Included in the discovery (N = 1804) and first validation (N = 288) cohorts were participants who received 2 doses of the mRNA-1273 vaccine. The second validation cohort consisted of KTRs who subsequently received a third dose of any SARS-CoV-2 vaccine (N = 1401). All participants had no history of SARS-CoV-2 infection. A multivariable logistic prediction model was built using stepwise backward regression analysis with nonseroconversion as the outcome. RESULTS. The discovery cohort comprised 836 (46.3%) KTRs, the first validation cohort 124 (43.1%) KTRs, and the second validation cohort 358 (25.6%) KTRs who did not seroconvert. In the final multivariable model‚ 12 factors remained predictive for nonseroconversion: use of mycophenolate mofetil/mycophenolic acid (MMF/MPA); chronic lung disease, heart failure, and diabetes; increased age; shorter time after transplantation; lower body mass index; lower kidney function; no alcohol consumption; ≥2 transplantations; and no use of mammalian target of rapamycin inhibitors or calcineurin inhibitors. The area under the curve was 0.77 (95% confidence interval [CI], 0.74-0.79) in the discovery cohort after adjustment for optimism, 0.81 (95% CI, 0.76-0.86) in the first validation cohort, and 0.67 (95% CI, 0.64-0.71) in the second validation cohort. The strongest predictor was the use of MMF/MPA, with a dose-dependent unfavorable effect, which remained after 3 vaccinations. CONCLUSIONS. In a large sample of KTRs, we identify a selection of KTRs at high risk of nonseroconversion after SARS-CoV-2 vaccination. Modulation of MMF/MPA treatment before vaccination may help to optimize vaccine response in these KTRs. This model contributes to future considerations on alternative vaccination strategies

    Tumor Ulceration Does Not Fully Explain Sex Disparities in Melanoma Survival among Adolescents and Young Adults

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    Hypertension in kidney transplant recipients (KTRs) is a risk factor for cardiovascular mortality and graft loss. Data on the prevalence of hypertension and uncontrolled hypertension (uHT) in paediatric and young adult KTRs are scarce. Also, it is unknown whether 'transition' (the transfer from paediatric to adult care) influences control of hypertension. We assessed the prevalence of hypertension and uHT among Dutch paediatric and young adult KTRs and analysed the effects of transition. Additionally, we made an inventory of variations in treatment policies in Dutch transplant centres. Cross-sectional and longitudinal national data from living KTRs a parts per thousand currency sign30 years of age (a parts per thousand yen1-year post-transplant, eGFR > 20 mL/min) were extracted from the 'RICH Q' database, which comprises information about all Dutch KTRs <19 years of age, and the Netherlands Organ Transplant Registry database for adult KTRs (a parts per thousand yen18-30 years of age). We used both upper-limit blood pressure (BP) thresholds for treatment according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. uHT was defined as a BP above the threshold. A questionnaire on treatment policies was sent to paediatric and adult nephrologists at eight Dutch transplant centres. Hypertension and uHT were more prevalent in young adult KTRs (86.4 and 75.8%) than in paediatric KTRs (62.7 and 38.3%) according to the KDIGO definition. Time after transplantation was comparable between these groups. Longitudinal analysis showed no evidence of effect of transition on systolic BP or prevalence of uHT. Policies vary considerably between and within centres on the definition of hypertension, BP measurement and antihypertensive treatment. Average BP in KTRs increases continuously with age between 6 and 30 years. Young adult KTRs have significantly more uHT than paediatric KTRs according to KDIGO guidelines. Transition does not influence the prevalence of uHT

    Outcome and Predictors for Mortality in Patients with Cardiogenic Shock:A Dutch Nationwide Registry-Based Study of 75,407 Patients with Acute Coronary Syndrome Treated by PCI

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    It is important to gain more insight into the cardiogenic shock (CS) population, as currently, little is known on how to improve outcomes. Therefore, we assessed clinical outcome in acute coronary syndrome (ACS) patients treated by percutaneous coronary intervention (PCI) with and without CS at admission. Furthermore, the incidence of CS and predictors for mortality in CS patients were evaluated. The Netherlands Heart Registration (NHR) is a nationwide registry on all cardiac interventions. We used NHR data of ACS patients treated with PCI between 2015 and 2019. Among 75,407 ACS patients treated with PCI, 3028 patients (4.1%) were identified with CS, respectively 4.3%, 3.9%, 3.5%, and 4.3% per year. Factors associated with mortality in CS were age (HR 1.02, 95%CI 1.02-1.03), eGFR (HR 0.98, 95%CI 0.98-0.99), diabetes mellitus (DM) (HR 1.25, 95%CI 1.08-1.45), multivessel disease (HR 1.22, 95%CI 1.06-1.39), prior myocardial infarction (MI) (HR 1.24, 95%CI 1.06-1.45), and out-of-hospital cardiac arrest (OHCA) (HR 1.71, 95%CI 1.50-1.94). In conclusion, in this Dutch nationwide registry-based study of ACS patients treated by PCI, the incidence of CS was 4.1% over the 4-year study period. Predictors for mortality in CS were higher age, renal insufficiency, presence of DM, multivessel disease, prior MI, and OHCA

    Characteristics, Treatment Strategies and Outcome in Cardiogenic Shock Complicating Acute Myocardial Infarction:A Contemporary Dutch Cohort

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    Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) is associated with high morbidity and mortality. Our study aimed to gain insights into patient characteristics, outcomes and treatment strategies in CS patients. Patients with CS who underwent percutaneous coronary intervention (PCI) between 2017 and 2021 were identified in a nationwide registry. Data on medical history, laboratory values, angiographic features and outcomes were retrospectively assessed. A total of 2328 patients with a mean age of 66 years and of whom 73% were male, were included. Mortality at 30 days was 39% for the entire cohort. Non-survivors presented with a lower mean blood pressure and increased heart rate, blood lactate and blood glucose levels (p-value for all &lt;0.001). Also, an increased prevalence of diabetes, multivessel coronary artery disease and a prior coronary event were found. Of all patients, 24% received mechanical circulatory support, of which the majority was via intra-aortic balloon pumps (IABPs). Furthermore, 79% of patients were treated with at least one vasoactive agent, and multivessel PCI was performed in 28%. In conclusion, a large set of hemodynamic, biochemical and patient-related characteristics was identified to be associated with mortality. Interestingly, multivessel PCI and IABPs were frequently applied despite a lack of evidence.</p

    SYSGENET: a meeting report from a new European network for systems genetics

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    The first scientific meeting of the newly established European SYSGENET network took place at the Helmholtz Centre for Infection Research (HZI) in Braunschweig, April 7-9, 2010. About 50 researchers working in the field of systems genetics using mouse genetic reference populations (GRP) participated in the meeting and exchanged their results, phenotyping approaches, and data analysis tools for studying systems genetics. In addition, the future of GRP resources and phenotyping in Europe was discussed

    The cardiovascular risk profile of middle-aged women with polycystic ovary syndrome

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    Contains fulltext : 220851.pdf (Publisher’s version ) (Open Access)OBJECTIVES: Contradictory results have been reported regarding the association between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD). We assessed the cardiometabolic phenotype and prevalence of CVD in middle-aged women with PCOS, compared with age-matched controls from the general population, and estimated 10-year CVD risk and cardiovascular health score. DESIGN: A cross-sectional study. PARTICIPANTS: 200 women aged >45 with PCOS, and 200 age-matched controls. MEASUREMENTS: Anthropometrics, insulin, lipid levels, prevalence of metabolic syndrome and type II diabetes. Ten-year Framingham risk score and the cardiovascular health score were calculated, and carotid intima-media thickness (cIMT) was measured. RESULTS: Mean age was 50.5 years (SD = 5.5) in women with PCOS and 51.0 years (SD = 5.2) in controls. Increased waist circumference, body mass index and hypertension were more often observed in women with PCOS (P < .001). In women with PCOS, the prevalence of type II diabetes and metabolic syndrome was not significantly increased and lipid levels were not different from controls. cIMT was lower in women with PCOS (P < .001). Calculated cardiovascular health and 10-year CVD risk were similar in women with PCOS and controls. CONCLUSIONS: Middle-aged women with PCOS exhibit only a moderately unfavourable cardiometabolic profile compared to age-matched controls, even though they present with an increased BMI and waist circumference. Furthermore, we found no evidence for increased (10-year) CVD risk or more severe atherosclerosis compared with controls from the general population. Long-term follow-up of women with PCOS is necessary to provide a definitive answer concerning long-term risk for CVD

    The cardiovascular risk profile of middle-aged women with polycystic ovary syndrome

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    Objectives: Contradictory results have been reported regarding the association between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD). We assessed the cardiometabolic phenotype and prevalence of CVD in middle-aged women with PCOS, compared with age-matched controls from the general population, and estimated 10-year CVD risk and cardiovascular health score. Design: A cross-sectional study. Participants: 200 women aged >45 with PCOS, and 200 age-matched controls. Measurements: Anthropometrics, insulin, lipid levels, prevalence of metabolic syndrome and type II diabetes. Ten-year Framingham risk score and the cardiovascular health score were calculated, and carotid intima-media thickness (cIMT) was measured. Results: Mean age was 50.5 years (SD = 5.5) in women with PCOS and 51.0 years (SD = 5.2) in controls. Increased waist circumference, body mass index and hypertension were more often observed in women with PCOS (P <.001). In women with PCOS, the prevalence of type II diabetes and metabolic syndrome was not significantly increased and lipid levels were not different from controls. cIMT was lower in women with PCOS (P <.001). Calculated cardiovascular health and 10-year CVD risk were similar in women with PCOS and controls. Conclusions: Middle-aged women with PCOS exhibit only a moderately unfavourable cardiometabolic profile compared to age-matched controls, even though they present with an increased BMI and waist circumference. Furthermore, we found no evidence for increased (10-year) CVD risk or more severe atherosclerosis compared with controls from the general population. Long-term follow-up of women with PCOS is necessary to provide a definitive answer concerning lon

    Has the Rate of CD4 Cell Count Decline before Initiation of Antiretroviral Therapy Changed over the Course of the Dutch HIV Epidemic among MSM?

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    Introduction:Studies suggest that the HIV-1 epidemic in the Netherlands may have become more virulent, leading to faster disease progression if untreated. Analysis of CD4 cell count decline before antiretroviral therapy (ART) initiation, a surrogate marker for disease progression, may be hampered by informative censoring as ART initiation is more likely with a steeper CD4 cell count decline.Methods:Development of CD4 cell count from 9 to 48 months after seroconversion was analyzed using a mixed-effects model and 2 models that jointly modeled CD4 cell counts and time to censoring event (start ART
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