Gastrointestinal (GI) cancers are a group of highly prevalent malignant tumors affecting the gastrointestinal tract. Globally, one in four cancer cases and one in three cancer deaths are estimated to be GI cancers. They can alter digestive and absorption functions, leading to severe malnutrition which may worsen the prognosis of the patients.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
August 2023
The gut-microbiome-brain axis plays a crucial role in the control of systemic metabolism and homeostasis. Recent research has shown that dietary habits and nutrients can affect immune system and inflammatory status by influencing various factors, including microbiome composition, microbial products release, gastrointestinal signaling molecules, and neurotransmitters. In addition, the gut microbiome affects the brain by altering levels of key brain transmitters, circulating cytokines, and short-chain fatty acids that can cross the blood-brain barrier.
View Article and Find Full Text PDFToday, the reactions of gas-phase organic peroxy radicals (RO) with unsaturated Volatile Organic Compounds (VOC) are expected to be negligible at room temperature and ignored in atmospheric chemistry. This assumption is based on combustion studies ( ≥ 360 K), which were the only experimental data available for these reactions until recently. These studies also reported epoxide formation as the only reaction channel.
View Article and Find Full Text PDFPatients with cognitive impairment have paid a heavy price for the coronavirus disease 2019 pandemic. Their clinical characteristics and their place of life made them particularly exposed to being infected and suffering from severe forms. The repercussions of the isolation measures also had significant repercussions on the expression of their neuropsychiatric symptoms and the burden on families and health care professionals.
View Article and Find Full Text PDFPlasmalogens are a specific glycerophospholipid subtype characterized by a vinyl-ether bound at their 1 moiety. Their biosynthesis is initiated in the peroxisome by dihydroxyacetone phosphate-acyltransferase (DHAPAT), which is encoded by the gene. Previous studies have shown that plasmalogen-deficient mice exhibit major physiological dysfunctions including several eye defects, among which abnormal vascular development of the retina and a reactive activation of macroglial Müller cells.
View Article and Find Full Text PDFAlterations of cholesterol metabolism have been described for many neurodegenerative pathologies, such as Alzheimer's disease in the brain and age-related macular degeneration in the retina. Recent evidence suggests that glaucoma, which is characterized by the progressive death of retinal ganglion cells, could also be associated with disruption of cholesterol homeostasis. In the present study we characterized cholesterol metabolism in a rat model of laser-induced intraocular hypertension, the main risk factor for glaucoma.
View Article and Find Full Text PDFWhite matter disorders of the central nervous system (CNS), such as multiple sclerosis (MS), lead to failure of nerve conduction and long-lasting neurological disabilities affecting a variety of sensory and motor systems, including vision. While most disease-modifying therapies target the immune and inflammatory response, the promotion of remyelination has become a new therapeutic avenue to prevent neuronal degeneration and promote recovery. Most of these strategies have been developed in short-lived rodent models of demyelination, which spontaneously repair and do not reflect the size, organization, and biology of the human CNS.
View Article and Find Full Text PDF() is an opportunistic pathogen causing infections ranging from superficial to life-threatening disseminated infections. In a susceptible host, is able to translocate through the gut barrier, promoting its dissemination into deeper organs. hyphae can invade human epithelial cells by two well-documented mechanisms: epithelial-driven endocytosis and -driven active penetration.
View Article and Find Full Text PDFPurpose: Cohen syndrome (CS) is a rare genetic disorder caused by variants of the VPS13B gene. CS patients are affected with a severe form of retinal dystrophy, and in several cases cataracts also develop. The purpose of this study was to investigate the mechanisms and risk factors for cataract in CS, as well as to report on cataract surgeries in CS patients.
View Article and Find Full Text PDFRetinal dystrophies and age-related macular degeneration related to photoreceptor degeneration can cause blindness. In blind patients, although the electrical activation of the residual retinal circuit can provide useful artificial visual perception, the resolutions of current retinal prostheses have been limited either by large electrodes or small numbers of pixels. Here we report the evaluation, in three awake non-human primates, of a previously reported near-infrared-light-sensitive photovoltaic subretinal prosthesis.
View Article and Find Full Text PDFMany neural interfaces used for therapeutic applications are based on extracellular electrical stimulation to control cell polarization and thus functional activity. Amongst them, retinal implants have been designed to restore visual perception in blind patients affected by photoreceptor degeneration diseases, such as age-related macular degeneration (AMD) or retinitis pigmentosa (RP). While designing such a neural interface, several aspects must be taken into account, like the stimulation efficiency related to the current distribution within the tissue, the bio-interface optimization to improve resolution and tissue integration, and the material biocompatibility associated with long-term aging.
View Article and Find Full Text PDFUsher syndrome type 1 (USH1) is a major cause of inherited deafness and blindness in humans. The eye disorder is often referred to as retinitis pigmentosa, which is characterized by a secondary cone degeneration following the rod loss. The development of treatments to prevent retinal degeneration has been hampered by the lack of clear evidence for retinal degeneration in mutant mice deficient for the Ush1 genes, which instead faithfully mimic the hearing deficit.
View Article and Find Full Text PDFThe majority of inherited retinal degenerations converge on the phenotype of photoreceptor cell death. Second- and third-order neurons are spared in these diseases, making it possible to restore retinal light responses using optogenetics. Viral expression of channelrhodopsin in the third-order neurons under ubiquitous promoters was previously shown to restore visual function, albeit at light intensities above illumination safety thresholds.
View Article and Find Full Text PDFUnlabelled: The HANAC syndrome is caused by mutations in the gene coding for collagen4a1, a major component of blood vessel basement membranes. Ocular symptoms include an increase in blood vessel tortuosity and occasional hemorrhages. To examine how vascular defects can affect neuronal function, we analyzed the retinal phenotype of a HANAC mouse model.
View Article and Find Full Text PDFPurpose: Taurine depletion is known to induce photoreceptor degeneration and was recently found to also trigger retinal ganglion cell (RGC) loss similar to the retinal toxicity of vigabatrin. Our objective was to study the topographical loss of RGCs and cone photoreceptors, with a distinction between the two cone types (S- and L- cones) in an animal model of induced taurine depletion.
Methods: We used the taurine transporter (Tau-T) inhibitor, guanidoethane sulfonate (GES), to induce taurine depletion at a concentration of 1% in the drinking water.
Diabetic retinopathy is a common complication of type 2 diabetes and the leading cause of blindness in adults of working age. The aim of this work was to study the repercussions of high fat diet (HFD) induced diabetes on the retina of Meriones shawi (M.sh).
View Article and Find Full Text PDFTwo retinal implants have recently received the CE mark and one has obtained FDA approval for the restoration of useful vision in blind patients. Since the spatial resolution of current vision prostheses is not sufficient for most patients to detect faces or perform activities of daily living, more electrodes with less crosstalk are needed to transfer complex images to the retina. In this study, we modelled planar and three-dimensional (3D) implants with a distant ground or a ground grid, to demonstrate greater spatial resolution with 3D structures.
View Article and Find Full Text PDFBoron doped nanocrystalline diamond is known as a remarkable material for the fabrication of sensors, taking advantage of its biocompatibility, electrochemical properties, and stability. Sensors can be fabricated to directly probe physiological species from biofluids (e.g.
View Article and Find Full Text PDFRetinal ganglion cells (RGCs) are spiking neurons, which send visual information to the brain, through the optic nerve. RGC degeneration occurs in retinal diseases, either as a primary process or secondary to photoreceptor loss. Mechanisms involved in this neuronal degeneration are still unclear and no drugs directly targeting RGC neuroprotection are yet available.
View Article and Find Full Text PDFRetinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease.
View Article and Find Full Text PDFIn 1970s, taurine deficiency was reported to induce photoreceptor degeneration in cats and rats. Recently, we found that taurine deficiency contributes to the retinal toxicity of vigabatrin, an antiepileptic drug. However, in this toxicity, retinal ganglion cells were degenerating in parallel to cone photoreceptors.
View Article and Find Full Text PDFThree-dimensional electrode geometries were proposed to increase the spatial resolution in retinal prostheses aiming at restoring vision in blind patients. We report here the results from a study in which finite-element modeling was used to design and optimize three-dimensional electrode geometries. Proposed implants exhibit an array of well-like shapes containing stimulating electrodes at their bottom, while the common return grid electrode surrounds each well on the implant top surface.
View Article and Find Full Text PDFA large number of chemical structures that interact with G-protein coupled receptors (GPCRs) have been disclosed in patents or published papers. Most of these compounds are selective for a given protein target; however, it is well recognized that some GPCR-drugs interact with multiple targets. Using a literature database, we have identified compounds that act on different GPCRs.
View Article and Find Full Text PDFThe 90-kDa heat shock protein (hsp90) has emerged as a new, promising target for cancer drug discovery. With the simultaneous disruption of a large range of oncogenic pathways, hsp90 inhibition results in either cytostasis or cell death. Diverse inhibitors of this molecular chaperone are currently under intensive study, and several have reached clinical trials.
View Article and Find Full Text PDFThe anti-epileptic drug vigabatrin induces an irreversible constriction of the visual field, but is still widely used to treat infantile spasms and some forms of epilepsy. We recently reported that vigabatrin-induced cone damage is due to a taurine deficiency. However, optic atrophy and thus retinal ganglion cell degeneration was also reported in children treated for infantile spasms.
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