Search results for " barrier"
showing 10 items of 540 documents
Assessment of alterations in barrier functionality and induction of proinflammatory and cytotoxic effects after sulfur mustard exposure of an in vitr…
2007
Acute lung injury after sulfur mustard (SM) inhalation is characterized by massive, localized hemorrhage and alveolar edema, which implies severe disruption of the vascular and distal airway barrier. In this study, we tested a recently established in vitro coculture model of the alveolo-capillary barrier for its applicability to investigate acute toxic effects of SM at the human respiratory unit. The epithelial compartment of cocultures was exposed to varying concentrations of SM (0-1000 microM; t = 30 min). Following exposure, functional and structural barrier integrity of cocultures was monitored over a period of 24 h. A 50% reduction of transbilayer electrical resistance (TER) within 12-…
Studying the Neurovascular Unit: An Improved Blood–Brain Barrier Model
2009
The blood–brain barrier (BBB) closely interacts with the neuronal parenchyma in vivo. To replicate this interdependence in vitro, we established a murine coculture model composed of brain endothelial cell (BEC) monolayers with cortical organotypic slice cultures. The morphology of cell types, expression of tight junctions, formation of reactive oxygen species, caspase-3 activity in BECs, and alterations of electrical resistance under physiologic and pathophysiological conditions were investigated. This new BBB model allows the application of techniques such as laser scanning confocal microscopy, immunohistochemistry, fluorescent live cell imaging, and electrical cell substrate impedance se…
Possible Pathomechanisms Responsible for Injury to the Central Nervous System in the Settings of Chronic Cerebrospinal Venous Insufficiency
2012
The discovery of stenoses in the azygous and internal jugular veins, the so-called chronic cerebrospinal venous insufficiency that accompanies multiple sclerosis, has enabled the reinterpretation of knowledge about this neurologic dis- ease. Pathologic venous outflow from the central nervous system appears to lead to two main problems. Firstly, it disas- sembles the blood-brain barrier and may allow the penetration of nervous parenchyma by glutamate and leukocytes. Sec- ondly, it may result in significant hypoperfusion of the brain and spinal cord. These two overlapping pathologies are likely to trigger plaques through caspase-1-driven pyroptosis of oligodendrocytes and to evoke neurodegene…
Neuronal Activity Drives Localized Blood-Brain-Barrier Transport of Serum Insulin-like Growth Factor-I into the CNS
2010
Upon entry into the central nervous system (CNS), serum insulin-like growth factor-1 (IGF-I) modulates neuronal growth, survival, and excitability. Yet mechanisms that trigger IGF-I entry across the blood-brain barrier remain unclear. We show that neuronal activity elicited by electrical, sensory, or behavioral stimulation increases IGF-I input in activated regions. Entrance of serum IGF-I is triggered by diffusible messengers (i.e., ATP, arachidonic acid derivatives) released during neurovascular coupling. These messengers stimulate matrix metalloproteinase-9, leading to cleavage of the IGF binding protein-3 (IGFBP-3). Cleavage of IGFBP-3 allows the passage of serum IGF-I into the CNS thro…
Peritumoral Edema in Meningiomas
1994
Although generally benign tumors, meningiomas may be associated with extensive peritumoral brain edema as seen on computed tomographic scans. Fifty-two patients with intracranial meningiomas were studied, and the hypodense areas on computed tomographic scans were related to the intraoperative microsurgical findings and to the sizes of the tumors. We have identified three kinds of tumor-brain interfaces characterized by different difficulties in microsurgical dissection: smooth type, transitional type, and invasive type. These different microsurgical interfaces seem to correlate very precisely with computed tomographic images of halo-like and finger-like hypodense areas, allowing prediction …
Probing the Multiple Structures of Vaterite through Combined Computational and Experimental Raman Spectroscopy.
2014
First-principles Raman spectra have been computed for several new vaterite structural models that have been recently proposed, and compared with spectra recorded on a set of biogenic, geological and synthetic samples. This set includes new measurements collected on Herdamania momus spicules (Great Barrier Reef, Queensland, Australia), which are known to have purity and crystallinity that are higher than for other biogenic samples. Overall, due to the close structural connection between the various models, the computed Raman spectra are found to be broadly similar. However, the spectra obtained for the two most stable models (monoclinic C2 and trigonal P3221, corresponding to two different p…
An ab initio CI study on the rotational barrier of the allyl anion
1986
All-electron and pseudopotential non-empirical calculations have been performed on C 2v and C s (syn, anti) allyl anion conformations. Using a double-zeta valence-shell basis set within the Epstein-Nesbet definition of the unperturbed Hamiltonian, a value about 19 kcal/mol is found for the barrier to rotation of the allyl anion. This value is the theoretical value obtained with greater accuracy, and the lowest one for the rotational barrier.
Intense laser effects on donor impurity in a cylindrical single and vertically coupled quantum dots under combined effects of hydrostatic pressure an…
2010
WOS: 000280235800010
The action of TH17 cells on blood brain barrier in multiple sclerosis and experimental autoimmune encephalomyelitis.
2019
Th17 cells, known as a highly pro-inflammatory subtype of Th cells, are involved very early in numerous aspects of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) neuropathology. A crucial event for the formation and accumulation of MS lesions is represented by the disruption of the blood brain barrier (BBB) in relapsing-remitting MS. Th17 cells also contribute to the progression of MS/EAE. These events will allow for the passage of inflammatory cells into the brain. Secondary to this, increased recruitment of neutrophils occurs, followed by increased protease activity that will continue to attract macrophages and monocytes, leading to brain inflammation with sus…
Isovaleraldehyde degradation using UV photocatalytic and dielectric barrier discharge reactors, and their combinations
2015
International audience; The abatement of isovaleraldehyde present in air was carried out in UV photocatalytic and dielectric barrier discharge reactors (and their combinations) for concentrations up to 150 mg C m−3 and air flow rates ranging from 4 to 10 m3 h−1. A kinetic study was performed following a Langmuir–Hinshelwood model. Photocatalytic treatment of an isovaleraldehyde and isovaleric acid mixture showed a clear inhibition of isovaleric acid abatement in presence of isovaleraldehyde. Dielectric barrier discharge treatment of isovaleraldehyde showed an increase of removal efficiency with applied voltage and a decrease with air flow rate and inlet concentration. Moreover, introduction…