Role of cytokines in experimental neurodegenerative and neuroinflammatory disorders

Altered expression of cytokines in response to body injury has diverse actions that can exacerbate, mediate, reduce or inhibit neuronal and myelin damage as well as influence the disease development in a variety of nervous system disorders, such as Alzheimer s disease (AD), multiple sclerosis and Guillain-Barré Syndrome (GBS). In these studies, we attempted to explore the possible roles of tumor necrosis factor (TNF)-α and interleukin (IL)-18 in experimental neurodegenerative and neuroinflammatory disorders. The role of TNF-α in kainic acid (KA)-induced excitotoxic neurodegeneration has been studied by comparing TNF receptor 1 (TNFR1) knockout (TNFR1-/-) mice with wild-type (WT) mice. After nasal application of KA, TNFR1-/- mice showed significantly severer seizures than WT mice. In addition, obvious neuronal damage, enhanced microglia activation and astrogliosis in hippocampus as well as increased locomotor activity were found in TNFR1-/- mice compared with WT controls. Moreover, CC chemokine receptor 3 expression on activated microglia was increased in TNFR1-/- mice after KA treatment as measured by flow cytometry. These data suggest that TNF-α may play a protective role via TNFR1 signalling in KA-induced neurodegeneration. Epidemiological studies concerning gender differences in AD support the higher prevalence and incidence of AD in women. The influence of age and gender on excitotoxic neurodegeneration has been investigated by treating C57BL/6 mice (aged females and males as well as adult females and males) with KA. The results showed that aged female mice were more sensitive to KA-induced excitotoxicity associated with severer seizure activity, increased locomotion and rearing in open-field test, prominent hippocampal neuronal damage, enhanced astrocyte proliferation compared with aged males, adult females and adult male mice, respectively. In addition, higher level of brain-derived neurotrophic factor in hippocampi of aged female mice was observed. These results denote that aged female mice are more sensitive to KA-induced excitotoxicity. IL-18 participates in the fundamental inflammatory processes, especially during aging. Based on the above results, we were interested in studying the role of IL-18 in KA-induced neurodegeneration in aged female C57BL/6 mice. We found that aged female IL-18-/- and WT mice showed similar responses to KA insult as demonstrated by comparable seizure activities, behavioral changes and neuronal cell death. However, aged female IL-18-/- mice failed to exhibit as strong microglial activation as WT mice. Interestingly, even though the number of activated microglia was less in KA-treated IL-18-/- mice than in KA-treated WT mice, the proportion of microglia that expressed the cytokines, TNF-α, IL-6 and IL-10 was higher in KA-treated IL-18-/- mice. Deficiency of IL-18 attenuates microglial activation after KA-induced excitotoxicity in aged brain, while the net effects of IL-18 deficiency are balanced by the enhancement of TNF-α, IL-6 and IL-10 production. To further explore the role of IL-18 in the neurodegeneration and neuroinflammation, another animal model - experimental autoimmune neuritis (EAN) was induced by immunization of mice (IL-18-/-) with P0 protein peptide 180-199. The clinical course was not significantly different between IL-18-/- and WT mice. The splenic mononuclear cell (MNC) proliferation was also similar in both animal groups. However, the percentages of interferon-γ, IL-10 and IL-12 positive cells were decreased among infiltrating MNC of cauda equina in IL-18-/- mice. This indicates that IL-18 deficiency inhibits the production of both Th1 and Th2 cytokines in the target organ of EAN. In summary, TNF-α may play a protective role via TNFR1 signalling in KA-induced neurodegeneration, while IL-18 may not be a key inflammatory cytokine in experimental neurodegenerative and neuroinflammatory disorders

Kainic Acid-Induced Neurotoxicity: Targeting Glial Responses and Glia-Derived Cytokines

Glutamate excitotoxicity contributes to a variety of disorders in the central nervous system, which is triggered primarily by excessive Ca2+ influx arising from overstimulation of glutamate receptors, followed by disintegration of the endoplasmic reticulum (ER) membrane and ER stress, the generation and detoxification of reactive oxygen species as well as mitochondrial dysfunction, leading to neuronal apoptosis and necrosis. Kainic acid (KA), a potent agonist to the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate class of glutamate receptors, is 30-fold more potent in neuro-toxicity than glutamate. In rodents, KA injection resulted in recurrent seizures, behavioral changes and subsequent degeneration of selective populations of neurons in the brain, which has been widely used as a model to study the mechanisms of neurodegenerative pathways induced by excitatory neurotransmitter. Microglial activation and astrocytes proliferation are the other characteristics of KA-induced neurodegeneration. The cytokines and other inflammatory molecules secreted by activated glia cells can modify the outcome of disease progression. Thus, anti-oxidant and anti-inflammatory treatment could attenuate or prevent KA-induced neurodegeneration. In this review, we summarized updated experimental data with regard to the KA-induced neurotoxicity in the brain and emphasized glial responses and glia-oriented cytokines, tumor necrosis factor-α, interleukin (IL)-1, IL-12 and IL-18

Real-Time Marker Level Set on GPU

International audienceLevel set methods have been extensively used to track the dynamical interfaces between different materials for physically based simulation, geometry modeling, oceanic modeling and other scientific and engineering applications. Due to the inherent Eulerian characteristics, interface evolution based on level set usually suffers from numerical diffusion, sharp feature missing and mass loss. Although some effective methods such as Particle Level Set (PLS) and Marker Level Set (MLS) have been proposed to tackle these difficulties, the complicated correction process and the high computational cost pose severe limitations for real-time applications. In this paper we provide an efficient parallel implementation of the Marker Level Set method on latest graphics hardware. Each step of the MLS method is fully mapped on GPU with an innovative combination of different computation techniques. Relying on GPU's parallelism and flexible programmability, the method provides real-time performance for large size 2D examples and moderate 3D examples, which is significantly faster than previous CPU based methods

The Effect of Artificial Intelligence (AI) on Firm Labor Structure

This paper aims to study the effect of AI on firm labor structure. Using a unique panel data of over 1300 publicly listed companies in China from 2007 to 2018, we study the effect of AI on firms’ labor composition measured by labor force’s education levels. We further compare the effect of AI on firms in the manufacturing sector to the effect on firms in the service sector. Our analysis generates two major findings. First, the use of AI leads to a larger labor demand increase for jobs requiring lower education levels than those requiring higher education levels. Second, the effect is stronger in the service sector than in the manufacturing sector. These findings contradict predictions of the “skill-biased technological change” (SJTB) and U-shaped “job polarization” effects proposed in the prior literature. We propose that “technology-enabled deskilling” effect is driving the effect of AI on labor structure

SimLocator: robust locator of similar objects in images

International audienceSimilar objects commonly appear in natural images, and locating and cutting out these objects can be tedious when using classical interactive image segmentation methods. In this paper, we propose SimLocator, a robust method oriented to locate and cut out similar objects with minimum user interaction. After extracting an arbitrary object template from the input image, candidate locations of similar objects are roughly detected by distinguishing the shape and color features of each image. A novel optimization method is then introduced to select accurate locations from the two sets of candidates. Additionally, a mattingbased method is used to improve the results and to ensure that all similar objects are located in the image. Finally, a method based on alpha matting is utilized to extract the precise object contours. To ensure the performance of the matting operation, this work has developed a new method for foreground extraction. Experiments show that SimLocator is more robust and more convenient to use compared to other more advanced repetition detection and interactive image segmentation methods, in terms of locating similar objects in images

Research progress on anterior segment optical coherence tomography in glaucoma

Glaucoma is the second blindness disease in the world, and there are more primary angle closed glaucoma in China. The anatomy changes of the anterior chamber have close relationships with the development of glaucoma. Anterior segment optical coherence tomography(AS-OCT)has the advantages of fast, non-contact, high resolution and accurate quantitative measurement, which provides a kind of important method for finding the pathogenesis of primary angle closed glaucoma, for early diagnosis and treatment of glaucoma, and for the postoperative evaluation of glaucoma

Content-Based Colour Transfer

International audienceThis paper presents a novel content-based method for transferring the colour patterns between images. Unlike previous methods that rely on image colour statistics, our method puts an emphasis on high-level scene content analysis. We first automatically extract the foreground subject areas and background scene layout from the scene. The semantic correspondences of the regions between source and target images are established. In the second step, the source image is re-coloured in a novel optimization framework, which incorporates the extracted content information and the spatial distributions of the target colour styles. A new progressive transfer scheme is proposed to integrate the advantages of both global and local transfer algorithms, as well as avoid the over-segmentation artefact in the result. Experiments how that with a better understanding of the scene contents, our method well preserves the spatial layout, the colour distribution and the visual coherence in the transfer process. As an interesting extension, our method can also be used to re-colour video clips with spatially-varied colour effects

Bis(μ-2-phenyl­quinoline-4-carboxyl­ato)-κ3 O,O′:O;κ3 O:O,O′-bis­[(2,2′-bipyridine-κ2 N,N′)(2-phenyl­quinoline-4-carboxyl­ato-κ2 O,O′)cadmium(II)]

The neutral binuclear title complex, [Cd2(C16H10NO2)4(C10H8N2)2], is centrosymmetric, with the inversion center generating the central (μ-O)2Cd2 bridge. The CdII ion is in a strongly distorted CdN2O5 penta­gonal-bipyramidal geometry, defined by two N atoms from one 2,2′-bipyridine ligand and five O atoms from three 2-phenyl­quinoline-4-carboxyl­ate ligands, one monodentate, two bidentate. Weak inter­molecular π–π inter­actions [centroid–centroid distance = 3.712 (3) Å] help to establish the packing of the structure