571 research outputs found

    Study of the Baryon-Antibaryon Low-Mass Enhancements in Charmless Three-body Baryonic B Decays

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    The angular distributions of the baryon-antibaryon low-mass enhancements seen in the charmless three-body baryonic B decays B+ -> p pbar K+, B0 -> p pbar Ks, and B0 -> p Lambdabar pi- are reported. A quark fragmentation interpretation is supported, while the gluonic resonance picture is disfavored. Searches for the Theta+ and Theta++ pentaquarks in the relevant decay modes and possible glueball states G with 2.2 GeV/c2 < M-ppbar < 2.4 GeV/c2 in the ppbar systems give null results. We set upper limits on the products of branching fractions, B(B0 -> Theta+ p)\times B(Theta+ -> p Ks) Theta++ pbar) \times B(Theta++ -> p K+) G K+) \times B(G -> p pbar) < 4.1 \times 10^{-7} at the 90% confidence level. The analysis is based on a 140 fb^{-1} data sample recorded on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.Comment: 14 pages, 13 figure files, update of hep-ex/0409010 for journal submisssio

    Discovery of a small molecule agonist of phosphatidylinositol 3-kinase p110ฮฑ that reactivates latent HIV-1

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    Combination antiretroviral therapy (cART) can effectively suppress HIV-1 replication, but the latent viral reservoir in resting memory CD4+ T cells is impervious to cART and represents a major barrier to curing HIV-1 infection. Reactivation of latent HIV-1 represents a possible strategy for elimination of this reservoir. In this study we describe the discovery of 1,2,9,10-tetramethoxy-7H-dibenzo[de,g]quinolin-7-one (57704) which reactivates latent HIV-1 in several cell-line models of latency (J89GFP, U1 and ACH-2). 57704 also increased HIV-1 expression in 3 of 4 CD8+-depleted blood mononuclear cell preparations isolated from HIV-1-infected individuals on suppressive cART. In contrast, vorinostat increased HIV-1 expression in only 1 of the 4 donors tested. Importantly, 57704 does not induce global T cell activation. Mechanistic studies revealed that 57704 reactivates latent HIV-1 via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. 57704 was found to be an agonist of PI3K with specificity to the p110a isoform, but not the p110ฮฒ, ฮด or ฮณ isoforms. Taken together, our work suggests that 57704 could serve as a scaffold for the development of more potent activators of latent HIV-1. Furthermore, it highlights the involvement of the PI3K/Akt pathway in the maintenance of HIV-1 latency. ยฉ 2014 Doyon et al

    Plasmodium vivax lineages: geographical distribution, tandem repeat polymorphism, and phylogenetic relationship

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    <p>Abstract</p> <p>Background</p> <p>Multi-drug resistance and severe/complicated cases are the emerging phenotypes of vivax malaria, which may deteriorate current anti-malarial control measures. The emergence of these phenotypes could be associated with either of the two <it>Plasmodium vivax </it>lineages. The two lineages had been categorized as Old World and New World, based on geographical sub-division and genetic and phenotypical markers. This study revisited the lineage hypothesis of <it>P. vivax </it>by typing the distribution of lineages among global isolates and evaluated their genetic relatedness using a panel of new mini-satellite markers.</p> <p>Methods</p> <p><it>18S SSU rRNA S-type </it>gene was amplified from 420 <it>Plasmodium vivax </it>field isolates collected from different geographical regions of India, Thailand and Colombia as well as four strains each of <it>P. vivax </it>originating from Nicaragua, Panama, Thailand (Pak Chang), and Vietnam (ONG). A mini-satellite marker panel was then developed to understand the population genetic parameters and tested on a sample subset of both lineages.</p> <p>Results</p> <p><it>18S SSU rRNA S-type </it>gene typing revealed the distribution of both lineages (Old World and New World) in all geographical regions. However, distribution of <it>Plasmodium vivax </it>lineages was highly variable in every geographical region. The lack of geographical sub-division between lineages suggests that both lineages are globally distributed. Ten mini-satellites were scanned from the <it>P. vivax </it>genome sequence; these tandem repeats were located in eight of the chromosomes. Mini-satellites revealed substantial allelic diversity (7-21, <it>AE </it>= 14.6 ยฑ 2.0) and heterozygosity (<it>He </it>= 0.697-0.924, <it>AE </it>= 0.857 ยฑ 0.033) per locus. Mini-satellite comparison between the two lineages revealed high but similar pattern of genetic diversity, allele frequency, and high degree of allele sharing. A Neighbour-Joining phylogenetic tree derived from genetic distance data obtained from ten mini-satellites also placed both lineages together in every cluster.</p> <p>Conclusions</p> <p>The global lineage distribution, lack of genetic distance, similar pattern of genetic diversity, and allele sharing strongly suggested that both lineages are a single species and thus new emerging phenotypes associated with vivax malaria could not be clearly classified as belonging to a particular lineage on basis of their geographical origin.</p

    Average Household Exposure to Newspaper Coverage about the Harmful Effects of Hormone Therapy and Population-Based Declines in Hormone Therapy Use

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    BACKGROUND: The news media facilitated the rapid dissemination of the findings from the estrogen plus progestin therapy arm of the Womenโ€™s Health Initiative (EPT-WHI). OBJECTIVE: To examine the relationship between the potential exposure to newspaper coverage and subsequent hormone therapy (HT) use. DESIGN/POPULATION: Population-based cohort of women receiving mammography at 7 sites (327,144 postmenopausal women). MEASUREMENTS: The outcome was the monthly prevalence of self-reported HT use. Circulation data for local, regional, and national newspapers was used to create zip-code level measures of the estimated average household exposure to newspaper coverage that reported the harmful effects of HT in July 2002. RESULTS: Women had an average potential household exposure of 1.4 articles. There was substantial variation in the level of average household exposure to newspaper coverage; women from rural sites received less than women from urban sites. Use of HT declined for all average potential exposure groups after the publication of the EPT-WHI. HT prevalence among women who lived in areas where there was an average household exposure of at least 3 articles declined significantly more (45 to 27%) compared to women who lived in areas with <1 article (43 to 31%) during each of the subsequent 5ย months (relative risks 0.86โ€“0.92; pโ€‰<โ€‰.006 for all). CONCLUSIONS: Greater average household exposure to newspaper coverage about the harms associated with HT was associated with a large population-based decline in HT use. Further studies should examine whether media coverage directly influences the health behavior of individual women

    Arabidopsis CaM Binding Protein CBP60g Contributes to MAMP-Induced SA Accumulation and Is Involved in Disease Resistance against Pseudomonas syringae

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    Salicylic acid (SA)-induced defense responses are important factors during effector triggered immunity and microbe-associated molecular pattern (MAMP)-induced immunity in plants. This article presents evidence that a member of the Arabidopsis CBP60 gene family, CBP60g, contributes to MAMP-triggered SA accumulation. CBP60g is inducible by both pathogen and MAMP treatments. Pseudomonas syringae growth is enhanced in cbp60g mutants. Expression profiles of a cbp60g mutant after MAMP treatment are similar to those of sid2 and pad4, suggesting a defect in SA signaling. Accordingly, cbp60g mutants accumulate less SA when treated with the MAMP flg22 or a P. syringae hrcC strain that activates MAMP signaling. MAMP-induced production of reactive oxygen species and callose deposition are unaffected in cbp60g mutants. CBP60g is a calmodulin-binding protein with a calmodulin-binding domain located near the N-terminus. Calmodulin binding is dependent on Ca2+. Mutations in CBP60g that abolish calmodulin binding prevent complementation of the SA production and bacterial growth defects of cbp60g mutants, indicating that calmodulin binding is essential for the function of CBP60g in defense signaling. These studies show that CBP60g constitutes a Ca2+ link between MAMP recognition and SA accumulation that is important for resistance to P. syringae

    Burden of malaria in pregnancy in Jharkhand State, India

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    <p>Abstract</p> <p>Background</p> <p>Past studies in India included only symptomatic pregnant women and thus may have overestimated the proportion of women with malaria. Given the large population at risk, a cross sectional study was conducted in order to better define the burden of malaria in pregnancy in Jharkhand, a malaria-endemic state in central-east India.</p> <p>Methods</p> <p>Cross-sectional surveys at antenatal clinics and delivery units were performed over a 12-month period at two district hospitals in urban and semi-urban areas, and a rural mission hospital. Malaria was diagnosed by Giemsa-stained blood smear and/or rapid diagnostic test using peripheral or placental blood.</p> <p>Results</p> <p>2,386 pregnant women were enrolled at the antenatal clinics and 718 at the delivery units. 1.8% (43/2382) of the antenatal clinic cohort had a positive diagnostic test for malaria (53.5% <it>Plasmodium falciparum</it>, 37.2% <it>Plasmodium vivax</it>, and 9.3% mixed infections). Peripheral parasitaemia was more common in pregnant women attending antenatal clinics in rural sites (adjusted relative risk [aRR] 4.31, 95%CI 1.84-10.11) and in those who were younger than 20 years (aRR 2.68, 95%CI 1.03-6.98). Among delivery unit participants, 1.7% (12/717) had peripheral parasitaemia and 2.4% (17/712) had placental parasitaemia. Women attending delivery units were more likely to be parasitaemic if they were in their first or second pregnancy (aRR 3.17, 95%CI 1.32-7.61), had fever in the last week (aRR 5.34, 95%CI 2.89-9.90), or had rural residence (aRR 3.10, 95%CI 1.66-5.79). Malaria control measures including indoor residual spraying (IRS) and untreated bed nets were common, whereas insecticide-treated bed nets (ITN) and malaria chemoprophylaxis were rarely used.</p> <p>Conclusion</p> <p>The prevalence of malaria among pregnant women was relatively low. However, given the large at-risk population in this malaria-endemic region of India, there is a need to enhance ITN availability and use for prevention of malaria in pregnancy, and to improve case management of symptomatic pregnant women.</p
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