398 research outputs found

    Role of DNA methylation in WNT5A Promoter B expression in Osteosarcoma (SaOS-2) cells.

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    WNT5A, a member of the WNT family of secreted proteins, activates the non-canonical WNT pathway, regulates developmental events and is involved in tissue homeostasis. Misregulation of WNT5A has been associated with various types of cancer including pancreatic, colorectal, breast, lung and osteosarcoma. Recent studies have shown that WNT5A expression in cancer cells involves non-genetic (epigenetic) changes. The WNT5A gene has two similar transcription start sites (termed promoter A and promoter B in this study) and transcription from these sites give rise to two different messages that encode different protein isoforms. Epigenetic studies to date have focused on the WNT5A promoter A, however our preliminary analysis found that promoter B transcripts are nearly absent in osteosarcoma cells, but present in normal osteoblasts. The goal of this study was to determine if the decrease in promoter B transcripts in osteosarcoma was due to DNA methylation. We identified 6 CpG islands in the WNT5A intron 1 region which contains promoter B and exon 1B, and compared them with data available in NCBI epigenomics website. The NCBI database was also screened for data on the methylation status of these islands in various other cell lines and cancer types. The database analysis shows that there is little or no methylation of Regions 1 - 6 in cells, that normally express WNT5A (fibroblast, chondrocytes, and mesenchymal stem cells). However, in some colorectal tumor tissue there is extensive methylation within intron 1. In adjacent normal colon mucosa tissue, Regions 3 and 4 showed some degree of methylation. Methylation status of the CpG islands in normal osteoblasts and osteosarcoma (SaOS-2) was determined using Sodium bisulfite sequencing. The sequencing data showed that CpG Regions 1 and 2 are unmethylated. Regions 3, 4 and 5 are completely methylated and Region 6 is partially methylated. In normal osteoblasts all 6 regions were unmethylated. A demethylation experiment using 5-Aza-cytidine was performed to determine if decrease in methylation would increase promoter B transcripts. Treatment of SaOS-2 cells with 1µM 5-Aza-cytidine resulted in a 120 fold increase of promoter B transcripts. The methylation data of SaOS-2 cells treated with 1µM 5-Aza-cytidine shows that CpG Region 6 is more prone to demethylation when compared to CpG islands 3, 4, 5. Two clones of Region 6 showed that 4 out of 5 CpG's analyzed were demethylated. 5 clones of Region 3 and 4 showed that only 1-2 CpG's were demethylated out of 24 CpG's in Region 3 and 27 CpG's in Region 4. Overall these results suggest that promoter B transcription is down regulated by DNA methylation of CpG Region 6 and Region 6 is more prone to demethylation compared to Regions 3, 4 and 5

    Thermoluminescence and optical absorption studies of highly pure KCl crystals

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    The existence of colored specimens of normally colorless minerals has been known for much longer than a century and has created excitement among mineralogists, physicists and chemists. Since early 1800, researchers have studied this coloration phenomenon through bleaching experiments, thermoluminescence, and reproduction of the coloration by electric sparks, ultraviolet light, high energy corpuscular radiation and chemical means. The discovery of ionizing radiation (X-rays and radioactivity) and the observation that this coloration could be reproduced by exposure to this radiation enhanced the interest which led to a more systematic and continuous study. Pohl1 did the most fundamental study of coloration on alkali halides and gave the name "color centers" to the "special electronic configuration in solids that gives rise to optical absorption in a normally transparent spectral region."2 The phenomenon involved in the coloration was realized to be important if one is to understand the electronic processes in solids

    Healthcare Utilization Patterns for Acute Febrile Illness in Bangladesh, Nepal, and Pakistan: Results from the Surveillance for Enteric Fever in Asia Project

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    Background: Characterizing healthcare-seeking patterns for acute febrile illness is critical for generating population-based enteric fever incidence estimates from facility-based surveillance data. Methods: We used a hybrid model in the Surveillance for Enteric Fever in Asia Project (SEAP) to assess incidence of enteric fever at 6 study hospitals in 3 countries. We recruited individuals presenting to the hospitals and obtained blood cultures to evaluate for enteric fever. For this analysis, we undertook cluster random household surveys in Dhaka, Bangladesh (2 sites); Karachi, Pakistan; Kathmandu, Nepal; and Kavrepalanchok, Nepal between January 2017 and February 2019, to ascertain care-seeking behavior for individuals with 1) fever for ≥3 consecutive days within the past 8 weeks; or 2) fever resulting in hospitalization within the past year. We also collected data about disease severity and household demographics and assets. We used mixed-effect multivariable logistic regression models to identify determinants of healthcare seeking at study hospitals and determinants of culture-confirmed enteric fever. Results: We enrolled 31 841 households (53926 children) in Bangladesh, 25510 households (84196 children and adults) in Nepal, and 21310 households (108031 children and adults) in Pakistan. Children <5 years were most likely to be taken to the study hospitals for febrile illness at all sites. Household wealth was positively correlated with healthcare seeking in 4 of 5 study sites, and at least one marker of disease severity was positively associated with healthcare seeking in 3 of 5 catchment areas. Wealth and disease severity were variably predictive of blood culture-confirmed enteric fever. Conclusions: Age, household wealth, and disease severity are important determinants of healthcare seeking for acute febrile illness and enteric fever risk in these communities, and should be incorporated into estimation models for enteric fever incidence

    Electrocardiography in people living at high altitude of Nepal.

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    OBJECTIVE: The main objective of this study was to estimate the prevalence of coronary heart disease (CHD) of high-altitude populations in Nepal determined by an ECG recordings and a medical history. METHODS: We carried out a cross-sectional survey of cardiovascular disease and risk factors among people living at four different altitude levels, all above 2800 m, in the Mustang and Humla districts of Nepal. 12-lead ECGs were recorded on 485 participants. ECG recordings were categorised as definitely abnormal, borderline or normal. RESULTS: No participant had Q waves to suggest past Q-wave infarction. Overall, 5.6% (95% CI 3.7 to 8.0) of participants gave a self-report of CHD. The prevalence of abnormal (or borderline abnormal) ECG was 19.6% (95% CI 16.1 to 23.4). The main abnormalities were: right axis deviation in 5.4% (95% CI 3.5 to 7.7) and left ventricular hypertrophy by voltage criteria in 3.5% (95% CI 2.0 to 5.5). ECG abnormalities were mainly on the left side of the heart for Mustang participants (Tibetan origin) and on the right side for Humla participants (Indo-Aryans). There was a moderate association between the probability of abnormal (or borderline abnormal) ECG and altitude when adjusted for potential confounding variables in a multivariate logistic model; with an OR for association per 1000 m elevation of altitude of 2.83 (95% CI 1.07 to 7.45), p=0.03. CONCLUSIONS: Electrocardiographic evidence suggests that although high-altitude populations do not have a high prevalence of CHD, abnormal ECG findings increase by altitude and risk pattern varies by ethnicity

    Screen or not to screen for peripheral arterial disease: Guidance from a decision model

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    __Abstract__ Background: Asymptomatic Peripheral Arterial Disease (PAD) is associated with greater risk of acute cardiovascular events. This study aims to determine the cost-effectiveness of one time only PAD screening using Ankle Brachial Index (ABI) test and subsequent anti platelet preventive treatment (low dose aspirin or clopidogrel) in individuals at high risk for acute cardiovascular events compared to no screening and no treatment using decision analytic modelling. Methods. A probabilistic Markov model was developed to evaluate the life time cost-effectiveness of the strategy of selective PAD screening and consequent preventive treatment compared to no screening and no preventive treatment. The analysis was conducted from the Dutch societal perspective and to address decision uncertainty, probabilistic sensitivity analysis was performed. Results were based on average values of 1000 Monte Carlo simulations and using discount rates of 1.5% and 4% for effects and costs respectively. One way sensitivity analyses were performed to identify the two most influential model parameters affecting model outputs. Then, a two way sensitivity analysis was conducted for combinations of values tested for these two most influential parameters. Results: For the PAD screening strategy, life years and quality adjusted life years gained were 21.79 and 15.66 respectively at a lifetime cost of 26,548 Euros. Compared to no screening and treatment (20.69 life years, 15.58 Quality Adjusted Life Ye

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Pleiotropic genes for metabolic syndrome and inflammation

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    Metabolic syndrome (MetS) has become a health and financial burden worldwide. The MetS definition captures clustering of risk factors that predict higher risk for diabetes mellitus and cardiovascular disease. Our study hypothesis is that additional to genes influencing individual MetS risk factors, genetic variants exist that influence MetS and inflammatory markers forming a predisposing MetS genetic network. To test this hypothesis a staged approach was undertaken. (a) We analyzed 17 metabolic and inflammatory traits in more than 85,500 participants from 14 large epidemiological studies within the Cross Consortia Pleiotropy Group. Individuals classified with MetS (NCEP definition), versus those without, showed on average significantly different levels for most inflammatory markers studied. (b) Paired average correlations between 8 metabolic traits and 9 inflammatory markers from the same studies as above, estimated with two methods, and factor analyses on large simulated data, helped in identifying 8 combinations of traits for follow-up in meta-analyses, out of 130,305 possible combinations between metabolic traits and inflammatory markers studied. (c) We performed correlated meta-analyses for 8 metabolic traits and 6 inflammatory markers by using existing GWAS published genetic summary results, with about 2.5 million SNPs from twelve predominantly largest GWAS consortia. These analyses yielded 130 unique SNPs/genes with pleiotropic associations (a SNP/gene associating at least one metabolic trait and one inflammatory marker). Of them twenty-five variants (seven loci newly reported) are proposed as MetS candidates. They map to genes MACF1, KIAA0754, GCKR, GRB14, COBLL1, LOC646736-IRS1, SLC39A8, NELFE, SKIV2L, STK19, TFAP2B, BAZ1B, BCL7B, TBL2, MLXIPL, LPL, TRIB1, ATXN2, HECTD4, PTPN11, ZNF664, PDXDC1, FTO, MC4R and TOMM40. Based on large data evidence, we conclude that inflammation is a feature of MetS and several gene variants show pleiotropic genetic associations across phenotypes and might explain a part of MetS correlated genetic architecture. These findings warrant further functional investigation. (C) 2014 Elsevier Inc. All rights reserved

    Differential Gene Expression Changes in Children with Severe Dengue Virus Infections

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    Dengue virus infection is an impressively emerging disease that can be fatal in severe cases. It is not precisely clear why some patients progress to severe disease whereas most patients only suffer from a mild infection. In severe disease, a “cytokine storm” is induced, which indicates the release of a great number of inflammatory mediators (“cytokines”). Evidence suggested that a balance could be involved between protective and pathologic cytokine release patterns. We studied this concept in a cohort of Indonesian children with severe dengue disease using a gene expression profiling method

    Diversity of Antibiotic-Active Bacteria Associated with the Brown Alga Laminaria saccharina from the Baltic Sea

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    Bacteria associated with the marine macroalga Laminaria saccharina, collected from the Kiel Fjord (Baltic Sea, Germany), were isolated and tested for antimicrobial activity. From a total of 210 isolates, 103 strains inhibited the growth of at least one microorganism from the test panel including Gram-negative and Gram-positive bacteria as well as a yeast. Most common profiles were the inhibition of Bacillus subtilis only (30%), B. subtilis and Staphylococcus lentus (25%), and B. subtilis, S. lentus, and Candida albicans (11%). In summary, the antibiotic-active isolates covered 15 different activity patterns suggesting various modes of action. On the basis of 16S rRNA gene sequence similarities &gt;99%, 45 phylotypes were defined, which were classified into 21 genera belonging to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Phylogenetic analysis of 16S rRNA gene sequences revealed that four isolates possibly represent novel species or even genera. In conclusion, L. saccharina represents a promising source for the isolation of new bacterial taxa and antimicrobially active bacteria

    Chitohexaose Activates Macrophages by Alternate Pathway through TLR4 and Blocks Endotoxemia

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    Sepsis is a consequence of systemic bacterial infections leading to hyper activation of immune cells by bacterial products resulting in enhanced release of mediators of inflammation. Endotoxin (LPS) is a major component of the outer membrane of Gram negative bacteria and a critical factor in pathogenesis of sepsis. Development of antagonists that inhibit the storm of inflammatory molecules by blocking Toll like receptors (TLR) has been the main stay of research efforts. We report here that a filarial glycoprotein binds to murine macrophages and human monocytes through TLR4 and activates them through alternate pathway and in the process inhibits LPS mediated classical activation which leads to inflammation associated with endotoxemia. The active component of the nematode glycoprotein mediating alternate activation of macrophages was found to be a carbohydrate residue, Chitohexaose. Murine macrophages and human monocytes up regulated Arginase-1 and released high levels of IL-10 when incubated with chitohexaose. Macrophages of C3H/HeJ mice (non-responsive to LPS) failed to get activated by chitohexaose suggesting that a functional TLR4 is critical for alternate activation of macrophages also. Chitohexaose inhibited LPS induced production of inflammatory molecules TNF-α, IL-1β and IL-6 by macropahges in vitro and in vivo in mice. Intraperitoneal injection of chitohexaose completely protected mice against endotoxemia when challenged with a lethal dose of LPS. Furthermore, Chitohexaose was found to reverse LPS induced endotoxemia in mice even 6/24/48 hrs after its onset. Monocytes of subjects with active filarial infection displayed characteristic alternate activation markers and were refractory to LPS mediated inflammatory activation suggesting an interesting possibility of subjects with filarial infections being less prone to develop of endotoxemia. These observations that innate activation of alternate pathway of macrophages by chtx through TLR4 has offered novel opportunities to cell biologists to study two mutually exclusive activation pathways of macrophages being mediated through a single receptor
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