42 research outputs found

    Frequent use of paracetamol and risk of allergic disease among women in an Ethiopian population

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    Introduction The hypothesis that paracetamol might increase the risk of asthma and other allergic diseases have gained support from a range of independent studies. However, in studies based in developed countries, the possibility that paracetamol and asthma are associated through aspirin avoidance is difficult to exclude. Objectives To explore this hypothesis among women in a developing country, where we have previously reported aspirin avoidance to be rare. Methods In 2005/6 a population based cohort of 1065 pregnant women was established in Butajira, Ethiopia and baseline demographic data collected. At 3 years post birth, an interview-based questionnaire administered to 945 (94%) of these women collected data on asthma, eczema, and hay fever in the past 12 month, frequency of paracetamol use and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were also performed. The independent effects of paracetamol use on allergic outcomes were determined using multiple logistic regression analysis. Findings The prevalence of asthma, eczema and hay fever was 1.7%, 0.9% and 3.8% respectively; of any one of these conditions 5.5%, and of allergen sensitization 7.8%. Paracetamol use in the past month was reported by 29%, and associations of borderline significance were seen for eczema (adjusted OR (95% CI) = 8.51 (1.68 to 43.19) for 1–3 tablets and 2.19 (0.36 to 13.38) for β‰₯4 tablets, compared to no tablets in the past month; overall p = 0.055) and for β€˜any allergic condition’ (adjusted OR (95% CI) = 2.73 (1.22 to 6.11) for 1–3 tablets and 1.35 (0.67 to 2.70) for β‰₯4 tablets compared to 0 in the past month; overall p = 0.071). Conclusions This study provides further cross-sectional evidence that paracetamol use increases the risk of allergic disease

    Stimulatory MAIT cell antigens reach the circulation and are efficiently metabolised and presented by human liver cells.

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    OBJECTIVE Mucosal-associated invariant T (MAIT) cells are the most abundant T cells in human liver. They respond to bacterial metabolites presented by major histocompatibility complex-like molecule MR1. MAIT cells exert regulatory and antimicrobial functions and are implicated in liver fibrogenesis. It is not well understood which liver cells function as antigen (Ag)-presenting cells for MAIT cells, and under which conditions stimulatory Ags reach the circulation. DESIGN We used different types of primary human liver cells in Ag-presentation assays to blood-derived and liver-derived MAIT cells. We assessed MAIT cell stimulatory potential of serum from healthy subjects and patients with portal hypertension undergoing transjugular intrahepatic portosystemic shunt stent, and patients with inflammatory bowel disease (IBD). RESULTS MAIT cells were dispersed throughout healthy human liver and all tested liver cell types stimulated MAIT cells, hepatocytes being most efficient. MAIT cell activation by liver cells occurred in response to bacterial lysate and pure Ag, and was prevented by non-activating MR1 ligands. Serum derived from peripheral and portal blood, and from patients with IBD stimulated MAIT cells in MR1-dependent manner. CONCLUSION Our findings reveal previously unrecognised roles of liver cells in Ag metabolism and activation of MAIT cells, repression of which creates an opportunity to design antifibrotic therapies. The presence of MAIT cell stimulatory Ags in serum rationalises the observed activated MAIT cell phenotype in liver. Increased serum levels of gut-derived MAIT cell stimulatory ligands in patients with impaired intestinal barrier function indicate that intrahepatic Ag-presentation may represent an important step in the development of liver disease

    Shape-Based Tracking Allows Functional Discrimination of Two Immune Cell Subsets Expressing the Same Fluorescent Tag in Mouse Lung Explant

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    Dendritic Cells (DC) represent a key lung immune cell population, which play a critical role in the antigen presenting process and initiation of the adaptive immune response. The study of DCs has largely benefited from the joint development of fluorescence microscopy and knock-in technology, leading to several mouse strains with constitutively labeled DC subsets. However, in the lung most transgenic mice do express fluorescent protein not only in DCs, but also in closely related cell lineages such as monocytes and macrophages. As an example, in the lungs of CX3CR1+/gfp mice the green fluorescent protein is expressed mostly by both CD11b conventional DCs and resident monocytes. Despite this non-specific staining, we show that a shape criterion can discriminate these two particular subsets. Implemented in a cell tracking code, this quantified criterion allows us to analyze the specific behavior of DCs under inflammatory conditions mediated by lipopolysaccharide on lung explants. Compared to monocytes, we show that DCs move slower and are more confined, while both populations do not have any chemotactism-associated movement. We could generalize from these results that DCs can be automatically discriminated from other round-shaped cells expressing the same fluorescent protein in various lung inflammation models

    Anti-Diarrheal Mechanism of the Traditional Remedy Uzara via Reduction of Active Chloride Secretion

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    BACKGROUND AND PURPOSE: The root extract of the African Uzara plant is used in traditional medicine as anti-diarrheal drug. It is known to act via inhibition of intestinal motility, but malabsorptive or antisecretory mechanisms are unknown yet. EXPERIMENTAL APPROACH: HT-29/B6 cells and human colonic biopsies were studied in Ussing experiments in vitro. Uzara was tested on basal as well as on forskolin- or cholera toxin-induced Cl(-) secretion by measuring short-circuit current (I(SC)) and tracer fluxes of (22)Na(+) and (36)Cl(-). Para- and transcellular resistances were determined by two-path impedance spectroscopy. Enzymatic activity of the Na(+)/K(+)-ATPase and intracellular cAMP levels (ELISA) were measured. KEY RESULTS: In HT-29/B6 cells, Uzara inhibited forskolin- as well as cholera toxin-induced I(SC) within 60 minutes indicating reduced active chloride secretion. Similar results were obtained in human colonic biopsies pre-stimulated with forskolin. In HT-29/B6, the effect of Uzara on the forskolin-induced I(SC) was time- and dose-dependent. Analyses of the cellular mechanisms of this Uzara effect revealed inhibition of the Na(+)/K(+)-ATPase, a decrease in forskolin-induced cAMP production and a decrease in paracellular resistance. Tracer flux experiments indicate that the dominant effect is the inhibition of the Na(+)/K(+)-ATPase. CONCLUSION AND IMPLICATIONS: Uzara exerts anti-diarrheal effects via inhibition of active chloride secretion. This inhibition is mainly due to an inhibition of the Na(+)/K(+)-ATPase and to a lesser extent to a decrease in intracellular cAMP responses and paracellular resistance. The results imply that Uzara is suitable for treating acute secretory diarrhea

    Lack of Association of SULT1A1 R213H Polymorphism with Colorectal Cancer: A Meta-Analysis

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    BACKGROUND: A number of case-control studies were conducted to investigate the association of SULT1A1 R213H polymorphisms with colorectal cancer (CRC) in humans. But the results were not always consistent. We performed a meta-analysis to examine the association between the SULT1A1 R213H polymorphism and CRC. METHODS AND FINDINGS: Data were collected from the following electronic databases: PubMed, Elsevier Science Direct, Excerpta Medica Database, and Chinese Biomedical Literature Database, with the last report up to September 2010. A total of 12 studies including 3,549 cases and 5,610 controls based on the search criteria were involved in this meta-analysis. Overall, no significant association of this polymorphism with CRC was found (H versus R: ORβ€Š=β€Š1.04, 95%CIβ€Š=β€Š0.94-1.16, Pβ€Š=β€Š0.46; HR+HH versus RR: ORβ€Š=β€Š1.01, 95%CIβ€Š=β€Š0.92-1.11, Pβ€Š=β€Š0.81; HH versus RR+HR: ORβ€Š=β€Š1.01, 95%CIβ€Š=β€Š0.74-1.38, Pβ€Š=β€Š0.95; HH versus RR: ORβ€Š=β€Š1.00, 95%CIβ€Š=β€Š0.77-1.31, Pβ€Š=β€Š0.98; HR versus RR: ORβ€Š=β€Š1.01, 95%CIβ€Š=β€Š0.92-1.11, Pβ€Š=β€Š0.86). In subgroup analysis, we also did not find any significant association in Cauasians (H versus R: ORβ€Š=β€Š1.02, 95%CIβ€Š=β€Š0.92-1.15, Pβ€Š=β€Š0.68; HR+HH versus RR: ORβ€Š=β€Š0.99, 95%CIβ€Š=β€Š0.91-1.09, Pβ€Š=β€Š0.90; HH versus RR+HR: ORβ€Š=β€Š1.01, 95%CIβ€Š=β€Š0.73-1.39, Pβ€Š=β€Š0.97; HH versus RR: ORβ€Š=β€Š0.99, 95%CIβ€Š=β€Š0.75-1.31, Pβ€Š=β€Š0.94; HR versus RR: ORβ€Š=β€Š0.99, 95%CIβ€Š=β€Š0.90-1.09, Pβ€Š=β€Š0.85). The results were not materially altered after the studies which did not fulfill Hardy-Weinberg equilibrium were excluded (H versus R: ORβ€Š=β€Š1.06, 95%CIβ€Š=β€Š0.95-1.19, Pβ€Š=β€Š0.31; HR+HH versus RR: ORβ€Š=β€Š1.03, 95%CIβ€Š=β€Š0.93-1.13, Pβ€Š=β€Š0.56; HH versus RR+HR: ORβ€Š=β€Š1.10, 95%CIβ€Š=β€Š0.78-1.56, Pβ€Š=β€Š0.57; HH versus RR: ORβ€Š=β€Š1.09, 95%CIβ€Š=β€Š0.83-1.44, Pβ€Š=β€Š0.53; HR versus RR: ORβ€Š=β€Š1.02, 95%CIβ€Š=β€Š0.92-1.13, Pβ€Š=β€Š0.75). CONCLUSION: This meta-analysis demonstrates that there is no association between the SULT1A1 R213H polymorphism and CRC

    IL28B SNP rs12979860 Is a Critical Predictor for On-Treatment and Sustained Virologic Response in Patients with Hepatitis C Virus Genotype-1 Infection

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    Single nucleotide polymorphisms (SNPs) of interleukin-28B (IL28B) have received considerable interest for their association with sustained virological response (SVR) when treating patients of genotype-1 hepatitis C virus (GT1-HCV) chronic infection with pegylated interferon and ribavirin (PegIFN/RBV). This study was to investigate the predictive power of IL28B SNPs for on-treatment responses and SVR in treatment-naΓ―ve patients with GT1-HCV chronic infection.We analyzed ten SNPs of IL28B in 191 treatment-naΓ―ve patients with GT1-HCV chronic infection who received PegIFN/RBV. In these patients, rapid virological response (RVR), early virological response (EVR) and SVR were achieved in 69.6%, 95.8% and 68.6% of the patients, respectively. Multivariate analysis (odds ratio; 95% confidence interval; P value) indicated age (0.96; 0.93-0.99; 0.012), low baseline viral load (4.65; 2.23-9.66; <0.001) and CC genotype of rs12979860 (7.74; 2.55-23.53; <0.001) but no other SNPs were independent predictors for SVR. In addition, none of the ten SNPs examined were associated with baseline viral load and stages of liver fibrosis. Regarding RVR, low baseline viral load (2.83; 1.40-5.73; 0.004) and CC genotype of rs12979860 (10.52; 3.45-32.04; <0.001) were two critical predictors. As for EVR, only CC genotype of rs12979860 (36.21; 6.68-196.38; <0.001) was the predictor. Similarly, for end of treatment response (ETR), CC genotype of rs12979860 (15.42; 4.62-51.18; <0.001) was the only predictor. For patients with RVR, only low baseline viral load (3.90; 1.57-9.68; 0.003) could predict the SVR. For patients without RVR, only rs12979860 (4.60; 1.13-18.65; 0.033) was the predictor for SVR.rs12979860 is the critical predictor for RVR, EVR, ETR and SVR in treatment-naΓ―ve patients of GT1-HCV chronic infection. Furthermore, this SNP is the only predictor for SVR in patients without RVR. These results have provided evidence that rs12979860 is the ideal IL28B SNP for genetic testing in treating patients of GT1-HCV chronic infection

    TAT-Mediated Transduction of MafA Protein In Utero Results in Enhanced Pancreatic Insulin Expression and Changes in Islet Morphology

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    Alongside Pdx1 and Beta2/NeuroD, the transcription factor MafA has been shown to be instrumental in the maintenance of the beta cell phenotype. Indeed, a combination of MafA, Pdx1 and Ngn3 (an upstream regulator of Beta2/NeuroD) was recently reported to lead to the effective reprogramming of acinar cells into insulin-producing beta cells. These experiments set the stage for the development of new strategies to address the impairment of glycemic control in diabetic patients. However, the clinical applicability of reprogramming in this context is deemed to be poor due to the need to use viral vehicles for the delivery of the above factors. Here we describe a recombinant transducible version of the MafA protein (TAT-MafA) that penetrates across cell membranes with an efficiency of 100% and binds to the insulin promoter in vitro. When injected in utero into living mouse embryos, TAT-MafA significantly up-regulates target genes and induces enhanced insulin production as well as cytoarchitectural changes consistent with faster islet maturation. As the latest addition to our armamentarium of transducible proteins (which already includes Pdx1 and Ngn3), the purification and characterization of a functional TAT-MafA protein opens the door to prospective therapeutic uses that circumvent the use of viral delivery. To our knowledge, this is also the first report on the use of protein transduction in utero

    HCV Causes Chronic Endoplasmic Reticulum Stress Leading to Adaptation and Interference with the Unfolded Protein Response

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    BACKGROUND: The endoplasmic reticulum (ER) is the cellular site for protein folding. ER stress occurs when protein folding capacity is exceeded. This stress induces a cyto-protective signaling cascades termed the unfolded protein response (UPR) aimed at restoring homeostasis. While acute ER stress is lethal, chronic sub-lethal ER stress causes cells to adapt by attenuation of UPR activation. Hepatitis C virus (HCV), a major human pathogen, was shown to cause ER stress, however it is unclear whether HCV induces chronic ER stress, and if so whether adaptation mechanisms are initiated. We wanted to characterize the kinetics of HCV-induced ER stress during infection and assess adaptation mechanisms and their significance. METHODS AND FINDINGS: The HuH7.5.1 cellular system and HCV-transgenic (HCV-Tg) mice were used to characterize HCV-induced ER stress/UPR pathway activation and adaptation. HCV induced a wave of acute ER stress peaking 2-5 days post-infection, which rapidly subsided thereafter. UPR pathways were activated including IRE1 and EIF2Ξ± phosphorylation, ATF6 cleavage and XBP-1 splicing. Downstream target genes including GADD34, ERdj4, p58ipk, ATF3 and ATF4 were upregulated. CHOP, a UPR regulated protein was activated and translocated to the nucleus. Remarkably, UPR activity did not return to baseline but remained elevated for up to 14 days post infection suggesting that chronic ER stress is induced. At this time, cells adapted to ER stress and were less responsive to further drug-induced ER stress. Similar results were obtained in HCV-Tg mice. Suppression of HCV by Interferon-Ξ± 2a treatment, restored UPR responsiveness to ER stress tolerant cells. CONCLUSIONS: Our study shows, for the first time, that HCV induces adaptation to chronic ER stress which was reversed upon viral suppression. These finding represent a novel viral mechanism to manipulate cellular response pathways
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