262 research outputs found

    Chlamydia pneumoniae Infection of Monocytes in vitro Stimulates Innate and Adaptive Immune Responses Relevant to those in Alzheimer\u27s Disease.

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    Background: Alzheimer\u27s disease (AD) is a progressive neurodegenerative disorder in which infection with Chlamydia pneumoniae (Cpn) has been associated. Cpn is an obligate intracellular respiratory pathogen that may enter the central nervous system (CNS) following infection and trafficking of monocytes through the blood-brain barrier. Following this entry, these cells may secrete pro-inflammatory cytokines and chemokines that have been identified in the AD brain, which have been thought to contribute to AD neurodegeneration. The objectives of this work were: (i) to determine if Cpn infection influences monocyte gene transcript expression at 48 hours post-infection and (ii) to analyze whether pro-inflammatory cytokines are produced and secreted from these cells over 24 to 120 hours post-infection. Methods: Gene transcription was analyzed by RT-PCR using an innate and adaptive immunity microarray with 84 genes organized into 5 functional categories: inflammatory response, host defense against bacteria, antibacterial humoral response, septic shock, and cytokines, chemokines and their receptors. Statistical analysis of the results was performed using the Student\u27s t-test. P-values ā‰¤ 0.05 were considered to be significant. ELISA was performed on supernatants from uninfected and Cpn-infected THP1 monocytes followed by statistical analysis with ANOVA. Results: When Cpn-infected THP1 human monocytes were compared to control uninfected monocytes at 48 hours post-infection, 17 genes were found to have a significant 4-fold or greater expression, and no gene expression was found to be down-regulated. Furthermore, cytokine secretion (IL-1Ɵ, IL-6, IL-8) appears to be maintained for an extended period of infection. Conclusions: Utilizing RT-PCR and ELISA techniques, our data demonstrate that Cpn infection of THP1 human monocytes promotes an innate immune response and suggests a potential role in the initiation of inflammation in sporadic/late-onset Alzheimer\u27s disease

    Immunohistological detection of Chlamydia pneumoniae in the Alzheimer's disease brain

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    <p>Abstract</p> <p>Background</p> <p>Sporadic late-onset Alzheimer's disease (AD) appears to evolve from an interplay between genetic and environmental factors. One environmental factor that continues to be of great interest is that of <it>Chlamydia pneumoniae </it>infection and its association with late-onset disease. Detection of this organism in clinical and autopsy samples has proved challenging using a variety of molecular and histological techniques. Our current investigation utilized immunohistochemistry with a battery of commercially available anti-<it>C. pneumoniae </it>antibodies to determine whether <it>C. pneumoniae </it>was present in areas typically associated with AD neuropathology from 5 AD and 5 non-AD control brains.</p> <p>Results</p> <p>Immunoreactivity for <it>C. pneumoniae </it>antigens was observed both intracellularly in neurons, neuroglia, endothelial cells, and peri-endothelial cells, and extracellularly in the frontal and temporal cortices of the AD brain with multiple <it>C. pneumoniae</it>-specific antibodies. This immunoreactivity was seen in regions of amyloid deposition as revealed by immunolabeling with two different anti-beta amyloid antibodies. Thioflavin S staining, overlaid with <it>C. pneumoniae </it>immunolabeling, demonstrated no direct co-localization of the organism and amyloid plaques. Further, the specificity of <it>C. pneumoniae </it>labeling of AD brain sections was demonstrated using <it>C. pneumoniae </it>antibodies pre-absorbed against amyloid Ī² 1-40 and 1-42 peptides.</p> <p>Conclusions</p> <p>Anti-<it>C. pneumoniae </it>antibodies, obtained commercially, identified both typical intracellular and atypical extracellular <it>C. pneumoniae </it>antigens in frontal and temporal cortices of the AD brain. <it>C. pneumoniae</it>, amyloid deposits, and neurofibrillary tangles were present in the same regions of the brain in apposition to one another. Although additional studies are required to conclusively characterize the nature of Chlamydial immunoreactivity in the AD brain, these results further implicate <it>C. pneumoniae </it>infection with the pathogenesis of Alzheimer's disease.</p

    Detection of Bacterial Antigens and Alzheimer\u27s Disease-like Pathology in the Central Nervous System of BALB/c Mice Following Intranasal Infection with a Laboratory Isolate of Chlamydia pneumoniae

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    Pathology consistent with that observed in Alzheimerā€™s disease (AD) has previously been documented following intranasal infection of normal wild-type mice with Chlamydia pneumoniae (Cpn) isolated from an AD brain (96-41). In the current study, BALB/c mice were intranasally infected with a laboratory strain of Cpn, AR-39, and brain and olfactory bulbs were obtained at 1-4 months post-infection (pi). Immunohistochemistry for amyloid beta or Cpn antigens was performed on sections from brains of infected or mock-infected mice. Chlamydia-specific immunolabeling was identified in olfactory bulb tissues and in cerebrum of AR-39 infected mice. The Cpn specific labeling was most prominent at 1 month pi and the greatest burden of amyloid deposition was noted at 2 months pi, whereas both decreased at 3 and 4 months. Viable Cpn was recovered from olfactory bulbs of 3 of 3 experimentally infected mice at 1 and 3 months pi, and in 2 of 3 mice at 4 months pi. In contrast, in cortical tissues of infected mice at 1 and 4 months pi no viable organism was obtained. At 3 months pi, only 1 of 3 mice had a measurable burden of viable Cpn from the cortical tissues. Mock-infected mice (0 of 3) had no detectable Cpn in either olfactory bulbs or cortical tissues. These data indicate that the AR-39 isolate of Cpn establishes a limited infection predominantly in the olfactory bulbs of BALB/c mice. Although infection with the laboratory strain of Cpn promotes deposition of amyloid beta, this appears to resolve following reduction of the Cpn antigen burden over time. Our data suggest that infection with the AR-39 laboratory isolate of Cpn results in a different course of amyloid beta deposition and ultimate resolution than that observed following infection with the human AD-brain Cpn isolate, 96-41. These data further support that there may be differences, possibly in virulence factors, between Cpn isolates in the generation of sustainable AD pathology

    Chlamydia pneumoniae: An Etiologic Agent for Late-Onset Dementia

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    The disease known as late-onset Alzheimer\u27s disease is a neurodegenerative condition recognized as the single most common form of senile dementia. The condition is sporadic and has been attributed to neuronal damage and loss, both of which have been linked to the accumulation of protein deposits in the brain. Significant progress has been made over the past two decades regarding our overall understanding of the apparently pathogenic entities that arise in the affected brain, both for early-onset disease, which constitutes approximately 5% of all cases, as well as late-onset disease, which constitutes the remainder of cases. Observable neuropathology includes: neurofibrillary tangles, neuropil threads, neuritic senile plaques and often deposits of amyloid around the cerebrovasculature. Although many studies have provided a relatively detailed knowledge of these putatively pathogenic entities, understanding of the events that initiate and support the biological processes generating them and the subsequent observable neuropathology and neurodegeneration remain limited. This is especially true in the case of late-onset disease. Although early-onset Alzheimer\u27s disease has been shown conclusively to have genetic roots, the detailed etiologic initiation of late-onset disease without such genetic origins has remained elusive. Over the last 15 years, current and ongoing work has implicated infection in the etiology and pathogenesis of late-onset dementia. Infectious agents reported to be associated with disease initiation are various, including several viruses and pathogenic bacterial species. We have reported extensively regarding an association between late-onset disease and infection with the intracellular bacterial pathoge

    Cigarette brands with flavour capsules in the filter: Trends in use and brand perceptions among smokers in the USA, Mexico and Australia, 2012-2014

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    Objective To describe trends, correlates of use and consumer perceptions related to the product design innovation of flavour capsules in cigarette filters.&nbsp; Methods Quarterly surveys from 2012 to 2014 were analysed from an online consumer panel of adult smokers aged 18&ndash;64, living in the USA (n=6865 observations; 4154 individuals); Mexico (n=5723 observations; 3366 individuals); and Australia (n=5864 observations; 2710 individuals). Preferred brand varieties were classified by price (ie, premium; discount) and flavour (ie, regular; flavoured without capsule; flavoured with capsule). Participants reported their preferred brand variety's appeal (ie, satisfaction; stylishness), taste (ie, smoothness, intensity), and harm relative to other brands and varieties. GEE models were used to determine time trends and correlates of flavour capsule use, as well as associations between preferred brand characteristics (ie, price stratum, flavour) and perceptions of relative appeal, taste and harm.&nbsp; Results Preference for flavour capsules increased significantly in Mexico (6% to 14%) and Australia (1% to 3%), but not in the USA (4% to 5%). 18&ndash;24 year olds were most likely to prefer capsules in the USA (10%) and Australia (4%), but not Mexico. When compared to smokers who preferred regular brands, smokers who preferred brands with capsules viewed their variety of cigarettes as having more positive appeal (all countries), better taste (all countries), and lesser risk (Mexico, USA) than other brand varieties.&nbsp; Conclusions Results indicate that use of cigarettes with flavour capsules is growing, is associated with misperceptions of relative harm, and differentiates brands in ways that justify regulatory action

    Curriculum policy reform in an era of technical accountability: 'fixing' curriculum, teachers and students in English schools

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    Drawing on a Levinasian ethical perspective, the argument driving this paper is that the technical accountability movement currently dominating the educational system in England is less than adequate because it overlooks educatorsā€™ responsibility for ethical relations in responding to difference in respect of the other. Curriculum policy makes a significant contribution to the technical accountability culture through complicity in performativity, high-stakes testing and datafication, at the same time as constituting student and teacher subjectivities. I present two different conceptualizations of subjectivity and education, before engaging these in the analysis of data arising from an empirical study which investigated teachersā€™ and stakeholdersā€™ experiences of curriculum policy reform in ā€˜disadvantagedā€™ English schools. The studyā€™s findings demonstrate how a prescribed programme of technical curriculum regulation attempts to ā€˜fixā€™ or mend educational problems by ā€˜fixingā€™ or prescribing educational solutions. This not only denies ethical professional relations between students, teachers and parents, but also deflects responsibility for educational success from government to teachers and hastens the move from public to private educational provision. Complying with prescribed curriculum policy requirements shifts attention from broad philosophical and ethical questions about educational purpose as well as conferring a violence by assuming control over student and teacher subjectivities
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