166 research outputs found

    Cutaneous glucocorticoid receptor sensitivity and proinflammatory cytokine levels in antidepressant-resistant depression

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    ABSTRACT Background. There is evidence to indicate that peripheral glucocorticoid receptor (GR) function is reduced in major depression, and a possible molecular explanation for this is the impact of raised pro-inflammatory cytokines. The topical steroid vasoconstriction assay provides a convenient probe of peripheral GR function. The present study sought to assess the sensitivity of peripheral GRs in antidepressant-resistant major depressives and investigate the association between GR sensitivity and circulating plasma cytokines. Method. Nineteen antidepressant-resistant depressives together with age- and sex-matched healthy controls underwent the steroid vasoconstriction assay using three commercial preparations of corticosteroids containing clobetasol propionate 0.05%, betamethasone valerate 0.1%, and clobetasone butyrate 0.05%, corresponding to very potent, potent, and moderately potent steroid creams respectively. The pro-inflammatory cytokines, tumour necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6) were measured using enzyme-linked immunosorbent assays. The severity of the depressive episode was assessed using the Hamilton Depression Scale (HAMD). Results. Depressed subjects had a significantly reduced vasoconstriction response across all three strengths of steroid. They also had significantly higher concentrations of TNF-a and IL-6. There was a significant inverse correlation between TNF-a concentration and vasoconstriction response and also between the HAMD score and vasoconstriction response. Conclusions. These findings suggest that cutaneous GR function is abnormal in antidepressantresistant depression, that circulating TNF-a may play a significant role in this abnormality and that the efficacy of topical steroids in antidepressant-resistant depressives is reduced

    Small molecule inhibitors of Aβ-aggregation and neurotoxicity

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    Alzheimer disease (AD) is characterized pathologically by extracellular amyloid deposits composed of Aβ peptide, neurofibrillary tangles (NFTs) made up of hyperphosphorylated tau, and a deficit of cholinergic neurons in the basal forebrain. Presently, only symptomatic therapies are available for the treatment of AD and these therapies have a limited time frame of utility. Amyloid disorders represent the effects of chronic Aβ production and are not a secondary pathological effect caused by a distant trigger; therefore targeting Aβ is a viable pursuit. In this review, we will discuss the various small molecule anti-aggregation inhibitors that have been reported in the literature, with emphasis on compounds that are presently being investigated in clinical trials

    CD200 Receptor Controls Sex-Specific TLR7 Responses to Viral Infection

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    Immunological checkpoints, such as the inhibitory CD200 receptor (CD200R), play a dual role in balancing the immune system during microbial infection. On the one hand these inhibitory signals prevent excessive immune mediated pathology but on the other hand they may impair clearance of the pathogen. We studied the influence of the inhibitory CD200-CD200R axis on clearance and pathology in two different virus infection models. We find that lack of CD200R signaling strongly enhances type I interferon (IFN) production and viral clearance and improves the outcome of mouse hepatitis corona virus (MHV) infection, particularly in female mice. MHV clearance is known to be dependent on Toll like receptor 7 (TLR7)-mediated type I IFN production and sex differences in TLR7 responses previously have been reported for humans. We therefore hypothesize that CD200R ligation suppresses TLR7 responses and that release of this inhibition enlarges sex differences in TLR7 signaling. This hypothesis is supported by our findings that in vivo administration of synthetic TLR7 ligand leads to enhanced type I IFN production, particularly in female Cd200−/− mice and that CD200R ligation inhibits TLR7 signaling in vitro. In influenza A virus infection we show that viral clearance is determined by sex but not by CD200R signaling. However, absence of CD200R in influenza A virus infection results in enhanced lung neutrophil influx and pathology in females. Thus, CD200-CD200R and sex are host factors that together determine the outcome of viral infection. Our data predict a sex bias in both beneficial and pathological immune responses to virus infection upon therapeutic targeting of CD200-CD200R

    FSHD: copy number variations on the theme of muscular dystrophy

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    In humans, copy number variations (CNVs) are a common source of phenotypic diversity and disease susceptibility. Facioscapulohumeral muscular dystrophy (FSHD) is an important genetic disease caused by CNVs. It is an autosomal-dominant myopathy caused by a reduction in the copy number of the D4Z4 macrosatellite repeat located at chromosome 4q35. Interestingly, the reduction of D4Z4 copy number is not sufficient by itself to cause FSHD. A number of epigenetic events appear to affect the severity of the disease, its rate of progression, and the distribution of muscle weakness. Indeed, recent findings suggest that virtually all levels of epigenetic regulation, from DNA methylation to higher order chromosomal architecture, are altered at the disease locus, causing the de-regulation of 4q35 gene expression and ultimately FSHD

    Intestinal microbiota in human health and disease: the impact of probiotics

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    The complex communities of microorganisms that colonise the human gastrointestinal tract play an important role in human health. The development of culture-independent molecular techniques has provided new insights in the composition and diversity of the intestinal microbiota. Here, we summarise the present state of the art on the intestinal microbiota with specific attention for the application of high-throughput functional microbiomic approaches to determine the contribution of the intestinal microbiota to human health. Moreover, we review the association between dysbiosis of the microbiota and both intestinal and extra-intestinal diseases. Finally, we discuss the potential of probiotic microorganism to modulate the intestinal microbiota and thereby contribute to health and well-being. The effects of probiotic consumption on the intestinal microbiota are addressed, as well as the development of tailor-made probiotics designed for specific aberrations that are associated with microbial dysbiosis

    Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders

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    Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively

    Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging

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    Evidence-Based PET for Abdominal and Pelvic Tumours

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    Evidence-based data about the usefulness of positron emission tomography (PET) and hybrid imaging methods (PET/CT and PET/MRI) in abdominal and pelvic tumours have been collected and discussed in this chapter. These data were divided in three sections: (1) gastrointestinal tumours, (2) uro-genital tumours, (3) gynaecological tumours. Several pooled data (diagnostic and prognostic data), clinical settings (e.g. staging, restaging, treatment evaluation) and radiotracers as fluorine-18 fluorodeoxyglucose (18F-FDG), radiolabelled choline and prostate-specific membrane antigen (PSMA) were considered
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