372 research outputs found

    Full-Exon Resequencing Reveals Toll-Like Receptor Variants Contribute to Human Susceptibility to Tuberculosis Disease

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    Tuberculosis (TB) is the leading cause of death worldwide due to an infectious agent. Data have accumulated over decades suggesting that variability in human susceptibility to TB disease has a genetic component. Toll-like receptors (TLRs) play a critical role in initiating the innate immune response to many pathogens in mouse models, but little is known about their role in human infections. Human TLRs have been reported to recognize mycobacterial antigens and initiate an immune response. We tested the hypothesis that amino acid-altering polymorphisms in five TLRs were associated with susceptibility to TB disease using a population-based case-control study with 1,312 adult TB patients and controls. Full-coding region sequencing of the five TLR genes in all 1,312 subjects yielded a data set in excess of 16 Mb. Rare nonsynonymous polymorphisms in TLR6-TLR1-TLR10 were significantly overrepresented among African-American TB cases compared with ethnically-matched control subjects. Common nonsynonymous polymorphisms in TLR6-TLR1-TLR10 also were significantly associated with TB disease in certain ethnic groups. Among African Americans, homozygotes for the common-variant haplotype TLR1-248S, TLR1-602I, and TLR6-249S had a significantly increased TB disease risk. A transmission/disequilibrium test on an independent sample found that the TLR1-248S variant was preferentially transmitted to diseased children, thereby confirming disease association. These results are consistent with recent reports implicating TLR1 variants, including TLR1-602, in significantly altered innate immune responses. Also consistent with disease association, rare TLR6 variants were defective in their ability to mediate NF-ΞΊB signal transduction in transfected human cells. Taken together, the data suggest that variant TLRs contribute to human susceptibility to TB disease. Extensive full-exon resequencing was critical for revealing new information about the role of TLRs in human-pathogen interactions and the genetic basis of innate immune function

    Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells

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    Fluoride ion batteries are potential β€œnext-generation” electrochemical storage devices that offer high energy density. At present, such batteries are limited to operation at high temperatures because suitable fluoride ion–conducting electrolytes are known only in the solid state. We report a liquid fluoride ion–conducting electrolyte with high ionic conductivity, wide operating voltage, and robust chemical stability based on dry tetraalkylammonium fluoride salts in ether solvents. Pairing this liquid electrolyte with a copper–lanthanum trifluoride (Cu@LaF_3) core-shell cathode, we demonstrate reversible fluorination and defluorination reactions in a fluoride ion electrochemical cell cycled at room temperature. Fluoride ion–mediated electrochemistry offers a pathway toward developing capacities beyond that of lithium ion technology

    M-health and health promotion: the digital cyborg and surveillance society

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    The new mobile wireless computer technologies and social media applications using Web 2.0 platforms have recently received attention from those working in health promotion as a promising new way of achieving their goals of preventing ill-health and promoting healthy behaviours at the population level. There is very little critical examination in this literature of how the use of these digital technologies may affect the targeted groups, in terms of the implications for how individuals experience embodiment, selfhood and social relationships. This article addresses these issues, employing a range of social and cultural theories to do so. It is argued that m-health technologies produce a digital cyborg body. They are able to act not only as prostheses but also as interpreters of the body. The subject produced through the use of m-health technologies is constructed as both an object of surveillance and persuasion and as a responsible citizen who is willing and able to act on the health imperatives issuing forth from the technologies and to present their body/self as open to continual measurement and assessment. The implications of this new way of surveilling the body’s health are discussed

    Role of deficits in pathogen recognition receptors in infection susceptibility

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    This work was supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundação para a CiΓͺncia e Tecnologia (FCT) (IF/00735/2014 to A.C. and SFRH/BPD/96176/2013 to C.C.

    Genetic variants in the TIRAP gene are associated with increased risk of sepsis-associated acute lung injury

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    <p>Abstract</p> <p>Background</p> <p>Toll like receptors (TLRs) signaling pathways, including the adaptor protein Mal encoded by the TIRAP gene, play a central role in the development of acute lung injury (ALI). Recently, the <it>TIRAP </it>variants have been described association with susceptibility to inflammatory diseases. The aim of this study was to investigate whether genetic variants in <it>TIRAP </it>are associated with the development of ALI.</p> <p>Methods</p> <p>A case-control collection from Han Chinese of 298 healthy subjects, 278 sepsis-associated ALI and 288 sepsis alone patients were included. Three tag single nucleotide polymorphisms (SNPs) of the TIRAP gene and two additional SNPs that have previously showed association with susceptibility to other inflammatory diseases were genotyped by direct sequencing. The differences of allele, genotype and haplotype frequencies were evaluated between three groups.</p> <p>Results</p> <p>The minor allele frequencies of both rs595209 and rs8177375 were significantly increased in ALI patients compared with both healthy subjects (odds ratio (OR) = 1.47, 95% confidence interval (CI):1.15-1.88, P = 0.0027 and OR = 1.97, 95% CI: (1.38-2.80), P = 0.0001, respectively) and sepsis alone patients (OR = 1.44, 95% CI: 1.12-1.85, P = 0.0041 and OR = 1.82, 95% CI: 1.28-2.57, P = 0.00079, respectively). Haplotype consisting of these two associated SNPs strengthened the association with ALI susceptibility. The frequency of haplotype AG (rs595209A, rs8177375G) in the ALI samples was significantly higher than that in the healthy control group (OR = 2.13, 95% CI: 1.46-3.09, P = 0.00006) and the sepsis alone group (OR = 2.24, 95% CI: 1.52-3.29, P = 0.00003). Carriers of the haplotype CA (rs595209C, rs8177375A) had a lower risk for ALI compared with healthy control group (OR = 0.69, 95% CI: 0.54-0.88, P = 0.0003) and sepsis alone group (OR = 0.71, 95% CI: 0.55-0.91, P = 0.0006). These associations remained significant after adjustment for covariates in multiple logistic regression analysis and for multiple comparisons.</p> <p>Conclusions</p> <p>These results indicated that genetic variants in the TIRAP gene might be associated with susceptibility to sepsis-associated ALI in Han Chinese population. However, the association needs to be replicated in independent studies.</p

    Identification of Tuberculosis Susceptibility Genes with Human Macrophage Gene Expression Profiles

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    Although host genetics influences susceptibility to tuberculosis (TB), few genes determining disease outcome have been identified. We hypothesized that macrophages from individuals with different clinical manifestations of Mycobacterium tuberculosis (Mtb) infection would have distinct gene expression profiles and that polymorphisms in these genes may also be associated with susceptibility to TB. We measured gene expression levels of >38,500 genes from ex vivo Mtb-stimulated macrophages in 12 subjects with 3 clinical phenotypes: latent, pulmonary, and meningeal TB (nβ€Š=β€Š4 per group). After identifying differentially expressed genes, we confirmed these results in 34 additional subjects by real-time PCR. We also used a case-control study design to examine whether polymorphisms in differentially regulated genes were associated with susceptibility to these different clinical forms of TB. We compared gene expression profiles in Mtb-stimulated and unstimulated macrophages and identified 1,608 and 199 genes that were differentially expressed by >2- and >5-fold, respectively. In an independent sample set of 34 individuals and a subset of highly regulated genes, 90% of the microarray results were confirmed by RT-PCR, including expression levels of CCL1, which distinguished the 3 clinical groups. Furthermore, 6 single nucleotide polymorphisms (SNPs) in CCL1 were found to be associated with TB in a case-control genetic association study with 273 TB cases and 188 controls. To our knowledge, this is the first identification of CCL1 as a gene involved in host susceptibility to TB and the first study to combine microarray and DNA polymorphism studies to identify genes associated with TB susceptibility. These results suggest that genome-wide studies can provide an unbiased method to identify critical macrophage response genes that are associated with different clinical outcomes and that variation in innate immune response genes regulate susceptibility to TB

    Curative Effect of 18Ξ²-Glycyrrhetinic Acid in Experimental Visceral Leishmaniasis Depends on Phosphatase-Dependent Modulation of Cellular MAP Kinases

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    We earlier showed that 18Ξ²-glycyrrhetinic acid (GRA), a pentacyclic triterpenoid from licorice root, could completely cure visceral leishmaniasis in BALB/c mouse model. This was associated with induction of nitric oxide and proinflammatory cytokine production through the up regulation of NF-ΞΊB. In the present study we tried to decipher the underlying cellular mechanisms of the curative effect of GRA. Analysis of MAP kinase pathways revealed that GRA caused strong activation of p38 and to a lesser extent, ERK in bone marrow-derived macrophages (BMDM). Almost complete abrogation of GRA-induced cytokine production in presence of specific inhibitors of p38 and ERK1/2 confirmed the involvement of these MAP kinases in GRA-mediated responses. GRA induced mitogen- and stress-activated protein kinase (MSK1) activity in a time-dependent manner suggested that GRA-mediated NF-ΞΊB transactivation is mediated by p38, ERK and MSK1 pathway. As kinase/phosphatase balance plays an important role in modulating infection, the effect of GRA on MAPK directed phosphatases (MKP) was studied. GRA markedly reduced the expression and activities of three phosphatases, MKP1, MKP3 and protein phosphatase 2A (PP2A) along with a substantial reduction of p38 and ERK dephosphorylation in infected BMDM. Similarly in the in vivo situation, GRA treatment of L. donovani-infected BALB/c mice caused marked reduction of spleen parasite burden associated with concomitant decrease of individual phosphatase levels. However, activation of kinases also played an important role as the protective effect of GRA was significantly abrogated by pharmacological inhibition of p38 and ERK pathway. Curative effect of GRA may, therefore, be associated with restoration of proper cellular kinase/phosphatase balance, rather than modulation of either kinases or phosphatases

    Magnetic hyperthermia controlled drug release in the GI tract : solving the problem of detection

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    Drug delivery to the gastrointestinal (GI) tract is highly challenging due to the harsh environments any drug- delivery vehicle must experience before it releases it’s drug payload. Effective targeted drug delivery systems often rely on external stimuli to effect release, therefore knowing the exact location of the capsule and when to apply an external stimulus is paramount. We present a drug delivery system for the GI tract based on coating standard gelatin drug capsules with a model eicosane- superparamagnetic iron oxide nanoparticle composite coating, which is activated using magnetic hyperthermia as an on-demand release mechanism to heat and melt the coating. We also show that the capsules can be readily detected via rapid X-ray computed tomography (CT) and magnetic resonance imaging (MRI), vital for progressing such a system towards clinical applications. This also offers the opportunity to image the dispersion of the drug payload post release. These imaging techniques also influenced capsule content and design and the delivered dosage form. The ability to easily change design demonstrates the versatility of this system, a vital advantage for modern, patient-specific medicine
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