Publications by authors named "Koopmans B"

Intramuscular injection of botulinum neurotoxin type A (BoNT-A) is commonly used to improve or maintain the joint range of motion in young children with spasticity. However, the effectiveness of BoNT-A treatment is variable and movement limitations are recurrent. Here we show long-term effects of a single, bilateral abobotulinumtoxinA (aboBoNT-A) injection in the gastrocnemius medialis and soleus muscles of wild-type and spastic (B6.

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Aims: This study aimed to compare the effects of linear and branched fructooligosaccharides (FOS) extracted from chicory and grass (Lolium perenne), respectively on human microbiota composition, diversity, and metabolism.

Methods And Results: To test the effects of linear and branched FOS on human microbiota we used the artificial in vitro human colon model (TIM-2). Microbiota composition and diversity were assessed by V3-V4 16S rRNA metagenomic sequencing, followed by differential taxa abundance and alpha/beta diversity analyses.

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Isolation of sex differences as a key characteristic underlying neurobehavioral differentiation is an essential component of studies in neuroscience. The current study sought to address this concern by observing behavioral differences using an automated home cage system for neurobehavioral assessment, a method rapidly increasing in use due to advances in technology and advantages such as reduced handling stress and cross-lab variability. Sex differences in C57BL/6 mice arose for motor activity and circadian-linked behavior, with females being more active compared to males, and males having a stronger anticipatory increase in activity leading up to the onset of the light phase compared to females.

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Article Synopsis
  • Charcot-Marie-Tooth disease type 1A (CMT1A) is caused by a duplication of the PMP22 gene on chromosome 17, leading to disrupted myelination in peripheral nerves.
  • Through studies on CMT1A mouse models and patient-derived stem cells, researchers found significant downregulation of cholesterol and lipid metabolism, as well as disturbances in plasma membrane components and cell signaling pathways.
  • Interventions that stimulate autophagy and lipolysis showed potential for rescuing the negative effects of PMP22 duplication, suggesting that targeting lipid metabolism could be a therapeutic strategy for CMT1A.
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Recent advances in single-particle photothermal circular dichroism (PT CD) and photothermal magnetic circular dichroism (PT MCD) microscopy have shown strong promise for diverse applications in chirality and magnetism. Photothermal circular dichroism microscopy measures direct differential absorption of left- and right-circularly polarized light by a chiral nanoobject and thus can measure a pure circular dichroism signal, which is free from the contribution of circular birefringence and linear dichroism. Photothermal magnetic circular dichroism, which is based on the polar magneto-optical Kerr effect, can probe the magnetic properties of a single nanoparticle (of sizes down to 20 nm) optically.

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Electric control of magnetization dynamics in two-dimensional (2D) magnetic materials is an essential step for the development of novel spintronic nanodevices. Electrostatic gating has been shown to greatly affect the static magnetic properties of some van der Waals magnets, but the control over their magnetization dynamics is still largely unexplored. Here we show that the optically-induced magnetization dynamics in the van der Waals ferromagnet CrGeTe can be effectively controlled by electrostatic gates, with a one order of magnitude change in the precession amplitude and over 10% change in the internal effective field.

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In KMT2A-rearranged acute lymphoblastic leukemia (ALL), an aggressive malignancy, oncogenic KMT2A-fusion proteins inappropriately recruit DOT1L to promote leukemogenesis, highlighting DOT1L as an attractive therapeutic target. Unfortunately, treatment with the first-in-class DOT1L inhibitor pinometostat eventually leads to non-responsiveness. To understand this we established acquired pinometostat resistance in pediatric KMT2A::AFF1 B-ALL cells.

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Magnetic racetrack memory has significantly evolved and developed since its first experimental verification and is considered one of the most promising candidates for future high-density on-chip solid-state memory. However, both the lack of a fast and precise magnetic domain wall (DW) shifting mechanism and the required extremely high DW motion (DWM) driving current make the racetrack difficult to commercialize. Here, we propose a method for coherent DWM that is free from the above issues, which is driven by chirality switching (CS) and an ultralow spin-orbit-torque (SOT) current.

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Neuroblastoma is the most common extracranial solid tumor in children. A subgroup of high-risk patients is characterized by aberrations in the chromatin remodeller ATRX that is encoded by 35 exons. In contrast to other pediatric cancer where ATRX point mutations are most frequent, multi-exon deletions (MEDs) are the most frequent type of ATRX aberrations in neuroblastoma.

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Synthetic antiferromagnetic nanoplatelets (NPs) with a large perpendicular magnetic anisotropy (SAF-PMA NPs) have a large potential in future local mechanical torque-transfer applications for e.g., biomedicine.

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Background: Pediatric cancer is the leading cause of disease-related death in children and the need for better therapeutic options remains urgent. Due to the limited number of patients, target and drug development for pediatrics is often supplemented by data from studies focused on adult cancers. Recent evidence shows that pediatric cancers possess different vulnerabilities that should be explored independently from adult cancers.

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Charcot-Marie-Tooth disease type 1A (CMT1A) is the most prevalent hereditary demyelinating neuropathy. This autosomal, dominantly inherited disease is caused by a duplication on chromosome 17p which includes the peripheral myelin protein 22 (PMP22) gene. There is clinical evidence that the disability in CMT1A is to a large extend due to axonal damage rather than demyelination.

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Introduction: Mutations affecting the RAS-MAPK pathway occur frequently in relapsed neuroblastoma tumors and are associated with response to MEK inhibition . However, these inhibitors alone do not lead to tumor regression , indicating the need for combination therapy.

Methods And Results: high-throughput combination screening, we identified that the MEK inhibitor trametinib can be combined with BCL-2 family member inhibitors, to efficiently inhibit growth of neuroblastoma cell lines with RAS-MAPK mutations.

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Background: Immunotherapy in high-risk neuroblastoma (HR-NBL) does not live up to its full potential due to inadequate (adaptive) immune engagement caused by the extensive immunomodulatory capacity of HR-NBL. We aimed to tackle one of the most notable immunomodulatory processes in neuroblastoma (NBL), absence of major histocompatibility complex class I (MHC-I) surface expression, a process greatly limiting cytotoxic T cell engagement. We and others have previously shown that MHC-I expression can be induced by cytokine-driven immune modulation.

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The influence of protocol standardization between laboratories on their replicability of preclinical results has not been addressed in a systematic way. While standardization is considered good research practice as a means to control for undesired external noise (i.e.

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A 'toy model'-aimed at capturing the essential physics-is presented that jointly describes spin-polarized hot electron transport and spin pumping driven by local heating. These two processes both contribute to spin-current generation in laser-excited magnetic heterostructures. The model is used to compare the two contributions directly.

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Neuroblastoma is the most common extracranial solid tumor found in children and despite intense multi-modal therapeutic approaches, low overall survival rates of high-risk patients persist. Tumors with heterozygous loss of chromosome 11q and amplification are two genetically distinct subsets of neuroblastoma that are associated with poor patient outcome. Using an isogenic 11q deleted model system and high-throughput drug screening, we identify checkpoint kinase 1 (CHK1) as a potential therapeutic target for 11q deleted neuroblastoma.

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This study presents the design, fabrication and experimental demonstration of a magneto-photonic device that delivers non-volatile photonic memory functionality. The aim is to overcome the energy and speed bottleneck of back-and-forth signal conversion between the electronic and optical domains when retrieving information from non-volatile memory. The device combines integrated photonic components based on the InP membrane on silicon (IMOS) platform and a non-volatile, built-in memory element (ferromagnetic thin-film multilayers) realized as a top-cladding on the photonic waveguides (a post-processing step).

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We present a new approach to tuning-fork-based atomic force microscopy for utilizing advanced "tip-on-chip" probes with high sensitivity and broad compatibility. Usually, such chip-like probes with a size reaching 2 × 2 mm drastically perturb the oscillation of the tuning fork, resulting in poor performance in its intrinsic force sensing. Therefore, restoring initial oscillatory characteristics is necessary for regaining high sensitivity.

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Article Synopsis
  • * Researchers used a drug-repurposing strategy to test 4,191 FDA-approved compounds on KMT2A-rearranged infant ALL samples to find effective treatments with lower toxicity to non-leukemic bone marrow.
  • * The study identified several drug classes that activate p53 signaling, which is crucial for inducing cell death in leukemia cells, suggesting drug-induced p53 activation could be key for effective treatment strategies.
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Mild traumatic brain injury induced by low-intensity blast (LIB) exposure poses concerns in military personnel. Using an open-field, non-inertial blast model and assessments by conventional behavioral tests, our previous studies revealed early-phase anxiety-like behaviors in LIB-exposed mice. However, the impact of LIB upon long-term anxiety-like behaviors requires clarification.

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Spasticity is the most common neurological disorder associated with increased muscle contraction causing impaired movement and gait. The aim of this study was to characterize the physical performance, skeletal muscle function, and phenotype of mice with a hereditary spastic mutation (B6.Cg-Glrb/J).

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Neurocognitive consequences of blast-induced traumatic brain injury (bTBI) pose significant concerns for military service members and veterans with the majority of "invisible injury." However, the underlying mechanism of such mild bTBI by low-intensity blast (LIB) exposure for long-term cognitive and mental deficits remains elusive. Our previous studies have shown that mice exposed to LIB result in nanoscale ultrastructural abnormalities in the absence of gross or apparent cellular damage in the brain.

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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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