462 research outputs found

    Unique morphological characteristics of mitochondrial subtypes in the heart: the effect of ischemia and ischemic preconditioning.

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    RATIONALE: Three subsets of mitochondria have been described in adult cardiomyocytes - intermyofibrillar (IMF), subsarcolemmal (SSM), and perinuclear (PN). They have been shown to differ in physiology, but whether they also vary in morphological characteristics is unknown. Ischemic preconditioning (IPC) is known to prevent mitochondrial dysfunction induced by acute myocardial ischemia/reperfusion injury (IRI), but whether IPC can also modulate mitochondrial morphology is not known. AIMS: Morphological characteristics of three different subsets of adult cardiac mitochondria along with the effect of ischemia and IPC on mitochondrial morphology will be investigated. METHODS: Mouse hearts were subjected to the following treatments (N=6 for each group): stabilization only, IPC (3x5 min cycles of global ischemia and reperfusion), ischemia only (20 min global ischemia); and IPC and ischemia. Hearts were then processed for electron microscopy and mitochondrial morphology was assessed subsequently. RESULTS: In adult cardiomyocytes, IMF mitochondria were found to be more elongated and less spherical than PN and SSM mitochondria. PN mitochondria were smaller in size when compared to the other two subsets. SSM mitochondria had similar area to IMF mitochondria but their sphericity measures were similar to PN mitochondria. Ischemia was shown to increase the sphericity parameters of all 3 subsets of mitochondria; reduce the length of IMF mitochondria, and increase the size of PN mitochondria. IPC had no effect on mitochondrial morphology either at baseline or after ischemia. CONCLUSION: The three subsets of mitochondria in the adult heart are morphologically different. IPC does not appear to modulate mitochondrial morphology in adult cardiomyocytes

    MicroRNA expression profiles in pediatric dysembryoplastic neuroepithelial tumors.

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    © Springer Science+Business Media New York 2015Among noncoding RNAs, microRNAs (miRNAs) have been most extensively studied, and their biology has repeatedly been proven critical for central nervous system pathological conditions. The diagnostic value of several miRNAs was appraised in pediatric dysembryoplastic neuroepithelial tumors (DNETs) using miRNA microarrays and receiving operating characteristic curves analyses. Overall, five pediatric DNETs were studied. As controls, 17 samples were used: the FirstChoice Human Brain Reference RNA and 16 samples from deceased children who underwent autopsy and were not present with any brain malignancy. The miRNA extraction was carried out using the mirVANA miRNA Isolation Kit, while the experimental approach included miRNA microarrays covering 1211 miRNAs. Quantitative real-time polymerase chain reaction was performed to validate the expression profiles of miR-1909* and miR-3138 in all samples initially screened with miRNA microarrays. Our findings indicated that miR-3138 might act as a tumor suppressor gene when down-regulated and miR-1909* as a putative oncogenic molecule when up-regulated in pediatric DNETs compared to the control cohort. Subsequently, both miRNA signatures might serve as putative diagnostic biomarkers for pediatric DNETs.Peer reviewedFinal Accepted Versio

    Porcine FcγRIIb Mediates Enhancement of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Infection

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    Antibody-dependent enhancement (ADE) of virus infection caused by the uptake of virus-antibody complexes by FcγRs is a significant obstacle to the development of effective vaccines to control certain human and animal viral diseases. The activation FcγRs, including FcγRI and FcγRIIa have been shown to mediate ADE infection of virus. In the present paper, we showed that pocine FcγRIIb, an inhibitory FcγR, mediates ADE of PRRSV infection. Stable Marc-145 cell lines expressing poFcγRIIb (Marc-poFcγRII) were established. The relative yield of progeny virus was significantly increased in the presence of sub-neutralization anti-PRRSV antibody. The Fab fragment and normal porcine sera had no effect. Anti-poFcγRII antibody inhibited the enhancement of infection when cells were infected in the presence of anti-PRRSV antibody, but not when cells were infected in the absence of antibody. These results indicate that enhancement of infection in these cells by anti-PRRSV virus antibody is FcγRII-mediated. Identification of the inhibitory FcγR mediating ADE infection should expand our understanding of the mechanisms of pathogenesis for a broad range of infectious diseases and may open many approaches for improvements to the treatment and prevention of such diseases

    The first report of RPSA polymorphisms, also called 37/67 kDa LRP/LR gene, in sporadic Creutzfeldt-Jakob disease (CJD)

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    <p>Abstract</p> <p>Background</p> <p>Although polymorphisms of <it>PRNP</it>, the gene encoding prion protein, are known as a determinant affecting prion disease susceptibility, other genes also influence prion incubation time. This finding offers the opportunity to identify other genetic or environmental factor (s) modulating susceptibility to prion disease. Ribosomal protein SA (<it>RPSA</it>), also called 37 kDa laminin receptor precursor (LRP)/67 kDa laminin receptor (LR), acts as a receptor for laminin, viruses and prion proteins. The binding/internalization of prion protein is dependent for LRP/LR.</p> <p>Methods</p> <p>To identify other susceptibility genes involved in prion disease, we performed genetic analysis of <it>RPSA</it>. For this case-control study, we included 180 sporadic Creutzfeldt-Jakob disease (CJD) patients and 189 healthy Koreans. We investigated genotype and allele frequencies of polymorphism on <it>RPSA </it>by direct sequencing or restriction fragment length polymorphism (RFLP) analysis.</p> <p>Results</p> <p>We observed four single nucleotide polymorphisms (SNPs), including -8T>C (rs1803893) in the 5'-untranslated region (UTR) of exon 2, 134-32C>T (rs3772138) in the intron, 519G>A (rs2269350) in the intron and 793+58C>T (rs2723) in the intron on the <it>RPSA</it>. The 519G>A (at codon 173) is located in the direct PrP binding site. The genotypes and allele frequencies of the <it>RPSA </it>polymorphisms showed no significant differences between the controls and sporadic CJD patients.</p> <p>Conclusion</p> <p>These results suggest that these <it>RPSA </it>polymorphisms have no direct influence on the susceptibility to sporadic CJD. This was the first genetic association study of the polymorphisms of <it>RPSA </it>gene with sporadic CJD.</p

    Vitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials

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    In recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L

    First Observation of τ3πηντ\tau\to 3\pi\eta\nu_{\tau} and τf1πντ\tau\to f_{1}\pi\nu_{\tau} Decays

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    We have observed new channels for τ\tau decays with an η\eta in the final state. We study 3-prong tau decays, using the ηγγ\eta\to\gamma\gamma and \eta\to 3\piz decay modes and 1-prong decays with two \piz's using the ηγγ\eta\to\gamma\gamma channel. The measured branching fractions are \B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau}) =(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4} and \B(\tau^{-}\to \pi^{-}2\piz\eta\nu_{\tau} =(1.4\pm0.6\pm0.3)\times10^{-4}. We observe clear evidence for f1ηππf_1\to\eta\pi\pi substructure and measure \B(\tau^{-}\to f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}. We have also searched for η(958)\eta'(958) production and obtain 90% CL upper limits \B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5} and \B(\tau^{-}\to \pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Search for the Decays B^0 -> D^{(*)+} D^{(*)-}

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    Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one candidate signal event, with an expected background of 0.022 +/- 0.011 events. This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) = (5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0 -> D^{*+} D^{*-}) D^{*\pm} D^\mp and B^0 -> D^+ D^-, no significant excess of signal above the expected background level is seen, and we calculate the 90% CL upper limits on the branching fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+ D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter

    ΛΛˉ\Lambda\bar{\Lambda} Production in Two-Photon Interactions at CLEO

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    Using the CLEO detector at the Cornell e+ee^+e^- storage ring, CESR, we study the two-photon production of ΛΛˉ\Lambda \bar{\Lambda}, making the first observation of γγΛΛˉ\gamma \gamma \to \Lambda \bar{\Lambda}. We present the cross-section for γγΛΛˉ \gamma \gamma \to \Lambda \bar{\Lambda} as a function of the γγ\gamma \gamma center of mass energy and compare it to that predicted by the quark-diquark model.Comment: 10 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
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