247 research outputs found

    Method of creating a nano-sized recess

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    The invention relates to creating a nano-sized recess into a layer of material. For that, a first layer (100) is provided, which defines a first recess (101). The first layer (100) is then conformally covered with a second layer (107) such that the second layer evenly covers the boundaries of the first recess. In this way, the second layer defines a nano-sized recess. Furthermore, the invention relates to using such a structure with a second nano-sized recess for etching a nanoslit into a graphene layer. Furthermore, such a graphene layer with a nanoslit is described to be used for creating a crossed-nanoslit device for sequencing molecules

    Dysregulation of microtubule stability impairs morphofunctional connectivity in primary neuronal networks

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    Functionally related neurons assemble into connected networks that process and transmit electrochemical information. To do this in a coordinated manner, the number and strength of synaptic connections is tightly regulated. Synapse function relies on the microtubule (MT) cytoskeleton, the dynamics of which are in turn controlled by a plethora of MT-associated proteins, including the MT-stabilizing protein Tau. Although mutations in the Tau-encodingMAPT gene underlie a set of neurodegenerative disorders, termed tauopathies, the exact contribution of MT dynamics and the perturbation thereof to neuronal network connectivity has not yet been scrutinized. Therefore, we investigated the impact of targeted perturbations of MT stability on morphological (e.g., neurite- and synapse density) and functional (e.g., synchronous calcium bursting) correlates of connectivity in networks of primary hippocampal neurons. We found that treatment with MT-stabilizing or -destabilizing compounds impaired morphofunctional connectivity in a reversible manner. We also discovered that overexpression of MAPT induced significant connectivity defects, which were accompanied by alterations in MT dynamics and increased resistance to pharmacological MT depolymerization. Overexpression of a MAPT variant harboring the P301L point mutation in the MT-binding domain did far less, directly linking neuronal connectivity with Tau's MT binding affinity. Our results show that MT stability is a vulnerable node in tauopathies and that its precise pharmacological tuning may positively affect neuronal network connectivity. However, a critical balance in MT turnover causes it to be a difficult therapeutic target with a narrow operating window

    The cellular composition of the lung lining fluid gradually changes from bronchus to alveolus

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    Although large advances have recently been made mapping out the cellular composition of lung tissue using single cell sequencing, the composition and distribution of the cellular elements within the lining fluid of the lung has not been extensively studied. Here, we assessed the cellular composition of the lung lining fluid by performing a differential cell analysis on bronchoalveolar lavage fluid (BALF) and epithelial lining fluid (ELF) at four different locations within the lung in post-lung transplantation patients. The percentage of neutrophils and lymphocytes is reduced in more distal regions of the lungs, while the percentage of macrophages increases in these more distal regions. These data provide valuable information to determine which lung lining fluid sampling technique and location is best to use for measuring specific factors and biomarkers, and to increase the understanding of different cell populations in specific lung regions

    Lowering the cutoff value for increment increases the sensitivity for the diagnosis of Lambert-Eaton myasthenic syndrome

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    Background: Increment of compound muscle action potential amplitude is a diagnostic hallmark of Lambert-Eaton myasthenic syndrome (LEMS). Making a diagnosis can be challenging, therefore, a proper cutoff for abnormal increment is highly relevant for improved recognition

    Pharmacological treatment of Lambert-Eaton Myasthenic Syndrome

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    Lambert-Eaton myasthenic syndrome (LEMS) is a very rare antibody-mediated autoimmune disease of the neuromuscular junction. Therapy can be divided in symptomatic treatment and immunosuppressive treatment. Symptomatic treatment with amifampridine is the only therapy currently authorized for use in LEMS patients. In the Netherlands the first choice drug is amifampridine base in an extended release formulation instead of the currently authorized amifampridine phosphate. This formulation has lower costs and is possibly safer due to lower peak concentrations. Other therapy used in LEMS patients is prescribed off-label and is based on experience in patients with myasthenia gravis. In many cases pyridostigmine is added as symptomatic treatment. In almost half of patients immunosuppressive therapy is started, mostly corticosteroids with or without azathioprine. Intravenous immunoglobulins and plasma exchange are used as emergency treatment. Currently no randomized clinical trials with new therapies are ongoing or announced in patients with LEMS, although multiple new therapies for myasthenia gravis are being investigated. These future therapies can be differentiated in symptomatic and immunomodulating drugs. The immunomodulating drugs can be further differentiated in early stage drugs which target the B-cell, later stage drugs which target the circulating antibodies and targeted therapy which have a disease-specific target. Some early and later stage immunomodulating drugs show promising results in myasthenia gravis although high cost and uncertain long term safety may be limiting for incorporating these drugs in LEMS treatment guidelines. Clinical trials in LEMS patients are lacking due to the rarity of the disease and we suggest the following requirements for future trials of potential new treatments: Sufficient power by performing multicenter or n-of-1 trials when appropriate, a cross-over design to reduce the number of patients and using a LEMS-specific quantitative primary outcome measure like the 3TUG score

    Sustained synchronized neuronal network activity in a human astrocyte co-culture system

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    Impaired neuronal network function is a hallmark of neurodevelopmental and neurodegenerative disorders such as autism, schizophrenia, and Alzheimer's disease and is typically studied using genetically modified cellular and animal models. Weak predictive capacity and poor translational value of these models urge for better human derived in vitro models. The implementation of human induced pluripotent stem cells (hiPSCs) allows studying pathologies in differentiated disease-relevant and patient-derived neuronal cells. However, the differentiation process and growth conditions of hiPSC-derived neurons are non-trivial. In order to study neuronal network formation and (mal) function in a fully humanized system, we have established an in vitro co-culture model of hiPSC-derived cortical neurons and human primary astrocytes that recapitulates neuronal network synchronization and connectivity within three to four weeks after final plating. Live cell calcium imaging, electrophysiology and high content image analyses revealed an increased maturation of network functionality and synchronicity over time for co-cultures compared to neuronal monocultures. The cells express GABAergic and glutamatergic markers and respond to inhibitors of both neurotransmitter pathways in a functional assay. The combination of this co-culture model with quantitative imaging of network morphofunction is amenable to high throughput screening for lead discovery and drug optimization for neurological diseases
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