629 research outputs found

    Si/Ge hole-tunneling double-barrier resonant tunneling diodes formed on sputtered flat Ge layers

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    We have demonstrated Si/Ge hole-tunneling double-barrier resonant tunneling diodes (RTDs) formed on flat Ge layers with a relaxation rate of 89% by our proposed method; in this method, the flat Ge layers can be directly formed on highly B-doped Si(001) substrates using our proposed sputter epitaxy method. The RTDs exhibit clear negative differential resistance effects in the static current–voltage (I–V) curves at room temperature. The quantized energy level estimation suggests that resonance peaks that appeared in the I–V curves are attributed to hole tunneling through the first heavy- and light-hole energy levels

    Differences in the Contribution of the CTLA4 Gene to Susceptibility to Fulminant and Type 1A Diabetes in Japanese Patients

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    OBJECTIVE—To examine the contribution of the CTLA4 gene in the susceptibility to fulminant type 1 diabetes and compare it with classic type 1A diabetes

    Targeted online liquid chromatography electron capture dissociation mass spectrometry for the localization of sites of in vivo phosphorylation in human Sprouty2

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    We demonstrate a strategy employing collision-induced dissociation for phosphopeptide discovery, followed by targeted electron capture dissociation (ECD) for site localization. The high mass accuracy and low background noise of the ECD mass spectra allow facile sequencing of coeluting isobaric phosphopeptides, with up to two isobaric phosphopeptides sequenced from a single mass spectrum. In contrast to the previously described neutral loss of dependent ECD method, targeted ECD allows analysis of both phosphotyrosine peptides and lower abundance phosphopeptides. The approach was applied to phosphorylation analysis of human Sprouty2, a regulator of receptor tyrosine kinase signaling. Fifteen sites of phosphorylation were identified, 11 of which are novel

    Amylase α-2A Autoantibodies: Novel Marker of Autoimmune Pancreatitis and Fulminant Type 1 Diabetes

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    OBJECTIVE— The pathogenesis of autoimmune pancreatitis (AIP) and fulminant type 1 diabetes remains unclear, although it is known that immune-mediated processes severely compromise the endocrine and exocrine functions in both diseases

    In silico mining identifies IGFBP3 as a novel target of methylation in prostate cancer

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    Promoter hypermethylation is central in deregulating gene expression in cancer. Identification of novel methylation targets in specific cancers provides a basis for their use as biomarkers of disease occurrence and progression. We developed an in silico strategy to globally identify potential targets of promoter hypermethylation in prostate cancer by screening for 5′ CpG islands in 631 genes that were reported as downregulated in prostate cancer. A virtual archive of 338 potential targets of methylation was produced. One candidate, IGFBP3, was selected for investigation, along with glutathione-S-transferase pi (GSTP1), a well-known methylation target in prostate cancer. Methylation of IGFBP3 was detected by quantitative methylation-specific PCR in 49/79 primary prostate adenocarcinoma and 7/14 adjacent preinvasive high-grade prostatic intraepithelial neoplasia, but in only 5/37 benign prostatic hyperplasia (P<0.0001) and in 0/39 histologically normal adjacent prostate tissue, which implies that methylation of IGFBP3 may be involved in the early stages of prostate cancer development. Hypermethylation of IGFBP3 was only detected in samples that also demonstrated methylation of GSTP1 and was also correlated with Gleason score ⩾7 (P=0.01), indicating that it has potential as a prognostic marker. In addition, pharmacological demethylation induced strong expression of IGFBP3 in LNCaP prostate cancer cells. Our concept of a methylation candidate gene bank was successful in identifying a novel target of frequent hypermethylation in early-stage prostate cancer. Evaluation of further relevant genes could contribute towards a methylation signature of this disease

    Visual field defects of optic neuritis in neuromyelitis optica compared with multiple sclerosis

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    <p>Abstract</p> <p>Background</p> <p>Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that predominantly affects the optic nerves and the spinal cord, and is possibly mediated by an immune mechanism distinct from that of multiple sclerosis (MS). Central scotoma is recognized as a characteristic visual field defect pattern of optic neuritis (ON), however, the differing pathogenic mechanisms of NMO and MS may result in different patterns of visual field defects for ON.</p> <p>Methods</p> <p>Medical records of 15 patients with NMO and 20 patients with MS having ON were retrospectively analyzed. A thorough systemic and neurological examination was performed for evaluating ON. The total number of relapses of ON and visual fields was investigated. Visual fields were obtained by Goldmann perimeter with each ON relapse.</p> <p>Results</p> <p>All MS patients experienced central scotoma, with 90% of them showing central scotoma with every ON relapse. However, 53% of NMO patients showed central scotoma with every ON relapse (p = 0.022), and the remaining 47% of patients experienced non-central scotoma (altitudinal, quadrant, three quadrant, hemianopia, and bitemporal hemianopia). Thirteen percent of NMO patients did not experience central scotoma during their disease course. Altitudinal hemianopia was the most frequent non-central scotoma pattern in NMO.</p> <p>Conclusions</p> <p>NMO patients showed higher incidence of non-central scotoma than MS, and altitudinal hemianopia may be characteristic of ON occurring in NMO. As altitudinal hemianopia is highly characteristic of ischemic optic neuropathy, we suggest that an ischemic mechanism mediated by anti-aquaporin-4 antibody may play a role in ON in NMO patients.</p

    Intestinal Epithelial-Derived TAK1 Signaling Is Essential for Cytoprotection against Chemical-Induced Colitis

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    We have previously reported that intestinal epithelium-specific TAK1 deleted mice exhibit severe inflammation and mortality at postnatal day 1 due to TNF-induced epithelial cell death. Although deletion of TNF receptor 1 (TNFR1) can largely rescue those neonatal phenotypes, mice harboring double deletion of TNF receptor 1 (TNFR1) and intestinal epithelium-specific deletion of TAK1 (TNFR1KO/TAK1(IE)KO) still occasionally show increased inflammation. This indicates that TAK1 is important for TNF-independent regulation of intestinal integrity.In this study, we investigated the TNF-independent role of TAK1 in the intestinal epithelium. Because the inflammatory conditions were sporadically developed in the double mutant TNFR1KO/TAK1(IE)KO mice, we hypothesize that epithelial TAK1 signaling is important for preventing stress-induced barrier dysfunction. To test this hypothesis, the TNFR1KO/TAK1(IE)KO mice were subjected to acute colitis by administration of dextran sulfate sodium (DSS). We found that loss of TAK1 significantly augments DSS-induced experimental colitis. DSS induced weight loss, intestinal damages and inflammatory markers in TNFR1KO/TAK1(IE)KO mice at higher levels compared to the TNFR1KO control mice. Apoptosis was strongly induced and epithelial cell proliferation was decreased in the TAK1-deficient intestinal epithelium upon DSS exposure. These suggest that epithelial-derived TAK1 signaling is important for cytoprotection and repair against injury. Finally, we showed that TAK1 is essential for interleukin 1- and bacterial components-induced expression of cytoprotective factors such as interleukin 6 and cycloxygenase 2.Homeostatic cytokines and microbes-induced intestinal epithelial TAK1 signaling regulates cytoprotective factors and cell proliferation, which is pivotal for protecting the intestinal epithelium against injury
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