Publications by authors named "Roelofs R"

Objective: Elevated levels of anti-amyloid-β (anti-Aβ) autoantibodies in cerebrospinal fluid (CSF) have been proposed as a diagnostic biomarker for cerebral amyloid angiopathy-related inflammation (CAA-RI). We aimed to independently validate the immunoassay for quantifying these antibodies and evaluate its diagnostic value for CAA-RI.

Methods: We replicated the immunoassay to detect CSF anti-Aβ autoantibodies using CSF from CAA-RI patients and non-CAA controls with unrelated disorders and further characterized its performance.

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Article Synopsis
  • * The 8th International RASopathies Symposium highlighted global cooperation in clinical care and research, focusing on building diverse patient groups and sharing discoveries to prepare for future interventional trials.
  • * The event included presentations from various stakeholders, including scientists and self-advocates, aimed at bridging knowledge gaps and fostering long-term research and advocacy partnerships to improve health outcomes for those with RASopathies.
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Background: Noonan syndrome spectrum disorders (NSSDs) constitute a group within the Rasopathies, and are one of the largest groups of syndromes with impact on multi-organ involvement known. The extreme variability of the clinical phenotype is, among others, due to the numerous different genes that are involved, and the differences in clinical presentation over the life span. We have studied the needs of patients and their relatives aiming to develop, evaluate and choose focus in research, medical care and policy to better meet their perspectives.

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Automated gait assessment tests are used in studies of disorders characterized by gait impairment. CatWalk XT is one of the first commercially available automated systems for analyzing the gait of rodents and is currently the most used system in peer-reviewed publications. This automated gait analysis system can generate a large number of gait parameters.

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Cognitive difficulties are argued to be common in patients with Noonan syndrome spectrum disorders (NSSDs), but findings are based on studies in which patients with variants in PTPN11 (prevalence ~50%) were overrepresented. The current study, using a structured clinical approach, describes the cognitive phenotype and psychopathology of 100 patients (aged 6 to 61 years) with nine different gene variants in the Ras/MAPK pathway underlying NSSDs (PTPN11n = 61, PTPN11 Noonan syndrome with multiple lentigines n = 3, SOS1n = 14, KRASn = 7, LZTR1n = 5, RAF1n = 4, SHOC2n = 2, CBLn = 2, SOS2n = 2). After weighted assessment and bootstrapping of the results of individual neuropsychological assessments and measures of psychopathology, cognitive performances in most variant groups were within the ranges of expectation.

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Hemolysis is known to cause acute kidney injury (AKI). The iron regulatory hormone hepcidin, produced by renal distal tubules, is suggested to exert a renoprotective role during this pathology. We aimed to elucidate the molecular mechanisms of renal hepcidin synthesis and its protection against hemoglobin-induced AKI.

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Kidney iron deposition may play a role in the progression of tubulointerstitial injury during chronic kidney disease. Here, we studied the molecular mechanisms of kidney iron loading in experimental focal segmental glomerulosclerosis (FSGS) and investigated the effect of iron-reducing interventions on disease progression. Thy-1.

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Objective: The opportunistic pathogen is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel -induced pathways in colon epithelial cells that could further explain how contributes to CRC development.

Design And Results: Transcription profiling of cultured CRC cells that were exposed to revealed the specific induction of oxidoreductase pathways.

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The reproducibility crisis (or replication crisis) in biomedical research is a particularly existential and under-addressed issue in the field of behavioral neuroscience, where, in spite of efforts to standardize testing and assay protocols, several known and unknown sources of confounding environmental factors add to variance. Human interference is a major contributor to variability both within and across laboratories, as well as novelty-induced anxiety. Attempts to reduce human interference and to measure more "natural" behaviors in subjects has led to the development of automated home-cage monitoring systems.

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Erythroferrone (ERFE), the erythroid regulator of iron metabolism, inhibits hepcidin to increase iron availability for erythropoiesis. ERFE plays a pathological role during ineffective erythropoiesis as occurs in X-linked sideroblastic anemia (XLSA) and β-thalassemia. Its measurement might serve as an indicator of severity for these diseases.

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This is the first controlled study regarding personality and psychopathology in adults with Noonan syndrome (NS). Anxiety, depression, alexithymia and symptoms of Attention Deficit-Hyperactivity Disorder and Autism Spectrum Disorder, have been previously described in NS. More information regarding personality and psychopathology in NS could improve mental health care for this population.

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Antibodies to Streptococcus gallolyticus subspecies gallolyticus (SGG) have been associated with colorectal cancer (CRC). Because SGG may correlate with impaired gut epithelia, we assessed the association of antibodies to bacterial flagellin C (FliC), a measure potentially related to this impairment, with CRC and the CRC-specific interaction with antibodies to SGG proteins. Antibodies to FliC and SGG pilus proteins Gallo2178 and Gallo2179 were measured in two independent studies, a combined study from Nijmegen and Detroit (93 CRC cases, 74 controls) and a replication data set including 576 cases and 576 controls from the Spanish multicenter multicase-control study (MCC-Spain).

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Purpose: Noonan syndrome (NS) is a genetic disorder that is associated with social cognitive problems. While treatment aimed at the improvement of social cognition is available for other neuropsychiatric disorders, no such interventions yet exist for NS patients. In this study, the development of the first social cognitive training for NS patients is described and its applicability and feasibility evaluated.

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The Resistive RAM (RRAM) technology is currently in a level of maturity that calls for its integration into CMOS compatible memory arrays. This CMOS integration requires a perfect understanding of the cells performance and reliability in relation to the deposition processes used for their manufacturing. In this paper, the impact of the precursor chemistries and process conditions on the performance of HfO based memristive cells is studied.

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With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production.

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Introduction: Although cognitive impairments in adults with Noonan syndrome seem to be limited to a low-average intelligence and slower processing speed, studies in children with Noonan syndrome have demonstrated more extensive cognitive problems. These include deficits in language skills, memory, attention, and executive functioning. This longitudinal study is the first to investigate intellectual development in a group of individuals with Noonan syndrome.

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Orally administrated iron is suspected to increase susceptibility to enteric infections among children in infection endemic regions. Here we investigated the effect of dietary iron on the pathology and local immune responses in intestinal infection models. Mice were held on iron-deficient, normal iron, or high iron diets and after 2 weeks they were orally challenged with the pathogen Citrobacter rodentium.

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Noonan syndrome (NS) and Turner syndrome (TS) are associated with cognitive problems and difficulties in affective information processing. While both phenotypes include short stature, facial dysmorphisms, and a webbed neck, genetic etiology and neuropsychological phenotype differ significantly. The present study examines putative differences in affective information processing and social assertiveness between adult women with NS and TS.

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Objective: Hypertensive disorders in pregnancy remain a major cause of maternal morbidity and mortality. Blood pressure control is essential for maternal and neonatal outcome. Therefore, we analyzed the potency and side effects of two treatment options (nicardipine compared to labetalol) in order to gain insight in improved treatment of severe hypertension during pregnancy and to evaluate the feasibility of a randomised controlled trial.

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Objective: To map the relation between metformin prescription and renal function in an outpatient setting. To investigate whether there is an association between renal function, metformin concentration and lactate concentration.

Design: Pilot for a prospective observational cohort study.

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Background: Executive functioning (EF) is important for adequate behavioural functioning and crucial for explaining symptoms of autism spectrum disorders (ASD) in individuals with normal intelligence, but is scarcely studied in individuals with ASD and intellectual disabilities (ID). We therefore study EF in an ID population by comparing performances on three frequently studied executive functions (shifting, inhibition and updating) between individuals with ASD and individuals without ASD. When studying ID populations, one should be aware of Spearman's Law of Diminishing Returns (SLODR), as it questions the possibility of measuring separate cognitive functions in ID populations.

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