Publications by authors named "McGeer E"

Background: Saliva, the most readily available body fluid, is the product of genes which are in constant activity throughout life. Measurement of saliva can predict the onset of some diseases years before their accumulation in vulnerable tissues causes clinical signs to appear. The purpose of this study was is to demonstrate current applications of saliva analysis and to predict and prevent disease progression.

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The means are now at hand to conquer Alzheimer's disease (AD). The method is to identify those at risk for the disease before clinical signs develop. That is followed by implementing measures that can effectively prevent disease development.

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Alzheimer's disease (AD) is characterized by deposits of amyloid-β protein (Aβ) in brain which become foci of inflammation. Neurons are destroyed by this inflammatory process, leading to the cognitive deficits which define AD clinical onset. Epidemiological studies indicate that nonsteroidal anti-inflammatory drugs (NSAIDs) can ameliorate this destructive process if they are started well before clinical signs develop.

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Complement is the backbone of our innate immune system. It is of ancient evolutionary origin, being traced back to horseshoe crabs 350 million years ago. It consists today of more than 25 proteins which must work together like clockwork to distinguish friend from foe.

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We have developed a non-invasive method of diagnosing Alzheimer's disease (AD), which can also predict the risk of its future onset. It is based on measuring salivary levels of amyloid-β protein terminating at position 42 (Aβ42). Brain deposits of this peptide are characteristic of AD.

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Two basic discoveries spurred research into inflammation as a driving force in the pathogenesis of Alzheimer's disease (AD). The first was the identification of activated microglia in association with the lesions. The second was the discovery that rheumatoid arthritics, who regularly consume anti-inflammatory agents, were relatively spared from the disease.

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Epidemiologic studies indicate that coffee consumption reduces the risk of Parkinson's disease and Alzheimer's disease. To determine the factors involved, we examined the protective effects of coffee components. The test involved prevention of neurotoxicity to SH-SY5Y cells that was induced by lipopolysaccharide plus interferon-γ or interferon-γ released from activated microglia and astrocytes.

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Background: Sodium thiosulfate (STS) is an industrial chemical which has also been approved for the treatment of certain rare medical conditions. These include cyanide poisoning and calciphylaxis in hemodialysis patients with end-stage kidney disease. Here, we investigated the anti-inflammatory activity of STS in our glial-mediated neuroinflammatory model.

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We here report synthesis for the first time of the acetyl salicylic acid dimer 5,5'-methylenebis(2-acetoxybenzoic acid) (DAS). DAS inhibits aberrant complement activation by selectively blocking factor D of the alternative complement pathway and C9 of the membrane attack complex. We have previously identified aurin tricarboxylic and its oligomers as promising agents in this regard.

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Bexarotene has been reported to reduce brain amyloid-β (Aβ) levels and to improve cognitive function in transgenic mouse models of Alzheimer's disease (AD). Four groups failed to fully replicate the primary results but the original authors claimed overall support for the general conclusions. Because of its potential clinical importance, the current work studied the effects of bexarotene using two animal species and highly relevant paradigms.

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Activated astrocytes, which can also be referred to as reactive astrocytes or astrogliosis, have been identified in affected regions of common neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis. Activated astrocytes may be beneficial, promoting neuronal survival due to their production of growth factors and neurotrophins. Activated astrocytes can also be detrimental to neighboring neurons in neuroinflammatory processes.

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LL-37 is the sole cathelicidin-derived antimicrobial peptide found in humans. It becomes active upon C-terminal cleavage of its inactive precursor hCAP18. In addition to antimicrobial action, it also functions as an innate immune system stimulant in many tissues of the body.

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Introduction: Activated microglia are associated with the progression of Alzheimer's disease (AD), as well as many other neurodegenerative diseases of aging. Microglia are therefore key targets for therapeutic intervention.

Areas Covered: β-amyloid (Aβ) deposits activate the complement system, which, in turn, stimulates microglia to release neurotoxic materials.

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Neuroinflammation is hypothesized to be a major driving force behind Alzheimer's disease (AD) pathogenesis. This hypothesis predicts that activated microglial cells can stimulate neurons to produce excessive amounts of β-amyloid protein (Aβ₁₋₄₂) and tau. The excess Aβ₁₋₄₂ forms extracellular deposits which stimulate further microglial activation.

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Objectives: Paroxysmal nocturnal hemoglobinemia (PNH) is a rare but serious condition characterized by complement-mediated red blood cell (RBC) hemolysis and episodic thrombotic attack. It results from decay accelerating factor (CD55), and protectin (CD59), becoming attached to RBC and other cell surfaces. Absence of these protective proteins leaves such cells vulnerable to self attack at the C3 convertase and membrane attack complex (MAC) stages of complement activation.

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The amyloid cascade hypothesis is widely accepted as the centerpiece of Alzheimer disease (AD) pathogenesis. It proposes that abnormal production of beta amyloid protein (Abeta) is the cause of AD and that the neurotoxicity is due to Abeta itself or its oligomeric forms. We suggest that this, in itself, cannot be the cause of AD because demonstrating such toxicity requires micromolar concentrations of these Abeta forms, while their levels in brain are a million times lower in the picomolar range.

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Hydrogen sulfide (H2 S) and nitric oxide (NO) have been described as gasotransmitters. Anti-inflammatory activity in the central and peripheral nervous systems may be one of their functions. Previously we demonstrated that several SH(-) donors including H2 S-releasing aspirin (S-ASA) exhibited anti-inflammatory and neuroprotective activity in vitro against toxins released by activated microglia and astrocytes.

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Aberrant complement activation is known to exacerbate the pathology in a spectrum of degenerative diseases of aging. We previously reported that aurin tricarboxylic acid (ATA) is an orally effective agent which prevents formation of the membrane attack complex of complement. It inhibits C9 attachment to tissue bound C5b678 and thus prevents bystander lysis of host cells.

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The GABAergic system is the main inhibitory neurotransmitter system in the vertebrate brain. Although it is well established that the GABAergic system is affected in neuropsychiatric disorders, in Alzheimer's disease (AD) it has been considered to be relatively spared. In this study we describe the immunohistochemical localization of the main enzymes of the GABAergic system; glutamate decarboxylase 65 (GAD65), GAD67, and GABA transferase (GABAT) in human brain.

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Astrocytes become activated in degenerative neurological diseases. In order to gain a greater understanding of the inflammatory factors released upon activation, we stimulated adult human astrocytes with interferon-gamma and examined the resultant conditioned medium (CM) for toxicity against differentiated human neuroblastoma SH-SY5Y cells. Cell death was measured by lactate dehydrogenase release assay.

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Complement plays a vital role in both the innate and adaptive immune systems. It recognizes a target, opsonizes it, generates anaphylatoxins, and directly kills cells through the membrane attack complex (MAC). This final function, which assembles C5b-9(n) on viable cell surfaces, can kill host cells through bystander lysis.

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The foundations of innate immunity in neurodegenerative disorders were first laid by Del Rio Hortega (1919). He identified and named microglia, recognizing them as cells of mesodermal origin. Van Furth in 1969 elaborated the monocyte phagocytic system with microglia as the brain representatives.

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Optineurin mutations cause adult-onset primary open-angle glaucoma and have been associated with some familial forms of amyotrophic lateral sclerosis (ALS). Optineurin is involved in many cellular processes and interacts with a variety of proteins, among them huntingtin (htt). Here we report that in Huntington's disease (HD) cortex, optineurin frequently occurs in neuronal intranuclear inclusions, and to a lesser extent, in inclusions in the neuropil and in perikarya.

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Earlier studies indicate that obovatol (OBO), isolated from a medicinal herb Magnolia obovata, has anti-inflammatory and anti-oxidative properties. Depletion of glutathione (GSH) in glial cells with the γ-glutamylcysteine synthase inhibitor D,L-buthionine-S,R-sulfoximine (BSO) is known to produce oxidative stress which, in turn, induces these cells to secrete inflammatory cytokines and other neurotoxic substances. In the present study, we investigated the ability of OBO to protect SH-SY5Y neuroblastoma cells from this effect.

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We have previously demonstrated that human astrocytes are GABAergic cells. Throughout the adult human brain, they express the GABA synthesizing enzyme GAD 67, the GABA metabolizing enzyme GABA-T, and the GABA(A) and GABA(B) receptors. GABA modulates the actions of microglia, indicating an important role for astrocytes beyond that of influencing neurotransmitter function.

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