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  • 1
    Publication Date: 2013-08-29
    Description: We developed a high-throughput Enzyme-linked immunosorbent assay (ELISA) for measuring α2,6-sialylated transferrin (Tf), based on inhibition of anti-Tf antibody binding to α2,6-sialylated Tf by a lectin, Sambucus sieboldiana Agglutinin (SSA). The inhibition was not observed with other glycoforms, such as periodate-treated, sialidase-treated and sialidase/galactosidase-treated Tf, suggesting that the assay was glycoform specific. This finding was applied to an automated latex-agglutination immunoassay, using SSA lectin as an inhibitor (SSA-ALI). The concentration of α2,6-sialylated Tf measured by SSA-ALI in human cerebrospinal fluid was correlated with that of ELISA ( r 2 = 0.8554), previously developed for measuring α2,6-sialylated Tf.
    Print ISSN: 0021-924X
    Electronic ISSN: 1756-2651
    Topics: Biology , Chemistry and Pharmacology
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  • 2
    Publication Date: 2014-06-26
    Description: Transferrin is an iron-transport protein which possesses N -glycans at Asn432 and Asn630 in humans. Transferrin glycoforms Tf-1 and Tf-2, previously identified in human cerebrospinal fluid, are defined as the lower and upper bands in gel electrophoresis, respectively. Importantly, the Tf-2/Tf-1 ratio is raised in idiopathic normal pressure hydrocephalus patients and is useful as a clinical marker. In order to gain insight into the relationship between transferrin glycoform and biological function, we performed comparative characterization of Tf-1, Tf-2 and serum transferrin (sTf). Mass spectrometric analyses confirmed that Tf-2 is modified with disialylated biantennary glycans at both of the two N -glycosylation sites, which are similar to the N -glycans of sTf. On the other hand, Tf-1 is site-specifically modified: Asn630 has biantennary agalacto-complex-type glycan with bisecting N -acetylglucosamine (GlcNAc) and core fucose while Asn432 is modified with complex/high mannose-type glycans and possibly single GlcNAc. Size exclusion chromatography and fluorescence correlation spectroscopy analysis revealed that the hydration volume of Tf-1 is slightly smaller than that of sTf. Our striking finding is that Tf-1 has an exposed hydrophobic surface as monitored by the fluorescence intensity and wavelength of a hydrophobic probe, 1-anilino-8-naphthalene sulfonate, whereas Tf-2 does not. These results suggest that the different N -glycan structure of Tf-1 lowers the apparent hydration volume and reveals a patch of hydrophobic surface on transferrin which is otherwise covered with sialoglycan in sTf and Tf-2. The carbohydrate deficiency in certain pathological conditions may also expose hydrophobic surface which may modulate the function and/or stability of transferrin.
    Print ISSN: 0959-6658
    Electronic ISSN: 1460-2423
    Topics: Biology , Medicine
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  • 3
    Publication Date: 2015-10-22
    Description: We investigate the relationship between X-ray and optical line emission in 340 nearby ( z ~= 0.04) AGN selected above 10 keV using Swift BAT. We find a weak correlation between the extinction corrected [O iii ] and hard X-ray luminosity ( $L_{\left[{\rm O}\,\small {III}\right] }^{\text{int}} \propto L_{14\text{--}195}$ ) with a large scatter ( R Pear = 0.64, = 0.62 dex) and a similarly large scatter with the intrinsic 2–10 keV to [O iii ] luminosities ( R Pear = 0.63, = 0.63 dex). Correlations of the hard X-ray fluxes with the fluxes of high-ionization narrow lines ([O iii ], He ii , [Ne iii ] and [Ne v ]) are not significantly better than with the low-ionization lines (H α, [S ii ]). Factors like obscuration or physical slit size are not found to be a significant part of the large scatter. In contrast, the optical emission lines show much better correlations with each other ( = 0.3 dex) than with the X-ray flux. The inherent large scatter questions the common usage of narrow emission lines as AGN bolometric luminosity indicators and suggests that other issues such as geometrical differences in the scattering of the ionized gas or long-term AGN variability are important.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
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  • 4
    Publication Date: 2015-03-28
    Description: We previously found that a lectin, Sambucus sieboldiana agglutinin (SSA), bound to α2,6-sialylated glycan epitopes on transferrin and inhibited anti-transferrin antibody binding to the antigen in ELISA (SSA inhibition). Here we report that SSA inhibition is applicable to immunohistochemistry, localizing α2,6-sialylated transferrin in the liver. Immunohistochemistry using anti-transferrin polyclonal antibody revealed that transferrin was detected in hepatocytes near interlobular veins. Addition of SSA lectin markedly attenuated the staining. Sialidase treatment of a liver section abolished SSA binding and concomitantly cancelled SSA inhibition, suggesting that SSA binding to glycan epitopes on the section was essential for the inhibition. To examine the importance of proximity between antigen epitopes and SSA-binding (glycosylation) sites, we prepared two anti-peptide antibodies against partial amino acid sequences of transferrin. One antibody (Tf-596Ab) is against a peptide sequence, Cys596-Ala614, which is proximal to N -glycosylation sites (Asn-432 and Asn-630). The other (Tf-120Ab) is against a peptide sequence, Val120-Cys137, distal to the sites. The staining signals of Tf-596Ab were reduced by the addition of SSA, whereas those of Tf-120Ab were reduced only a little. This result suggests that proximity of the antigen epitope to SSA binding sites is critical for SSA inhibition in immunohistochemistry.
    Print ISSN: 0021-924X
    Electronic ISSN: 1756-2651
    Topics: Biology , Chemistry and Pharmacology
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  • 5
    Publication Date: 2016-01-02
    Description: To understand the interactions between active galactic nuclei (AGNs) and star formation during the evolution of galaxies, we investigate 142 galaxies detected in both X-ray and 70 μm observations in the COSMOS (Cosmic Evolution Survey) field. All of our data are obtained from the archive X-ray point-source catalogues from Chandra and XMM–Newton observations, and the far-infrared 70 μm point-source catalogue from Spitzer-MIPS observations. Although the IRAC [3.6 μm]–[4.5 μm] versus [5.8 μm]–[8.0 μm] colours of our sample indicate that only ~63 per cent of our sources would be classified as AGNs, the ratio of the rest-frame 2–10 keV luminosity to the total infrared luminosity (8–1000 μm) shows that the entire sample has comparatively higher X-ray luminosity than that expected from pure star-forming galaxies, suggesting the presence of an AGN in all of our sources. From an analysis of the X-ray hardness ratio, we find that sources with both 70 μm and X-ray detection tend to have a higher hardness ratio relative to the whole X-ray-selected source population, suggesting the presence of more X-ray absorption in the 70 μm detected sources. In addition, we find that the observed far-infrared colours of 70 μm detected sources with and without X-ray emission are similar, suggesting the far-infrared emission could be mainly powered by star formation.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
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  • 6
    Publication Date: 2013-01-22
    Description: The aim of this paper is to study the growth of the multiplicities in length spectra on the Riemann surfaces derived from congruence subgroups of the modular group. Bogomolny–Leyvraz–Schmit ( Commun. Math. Phys. 176 (1996) 575–617) and Peter ( Commun. Math. Phys. 225 (2002) 171–189) proposed an asymptotic formula for the correlation of the multiplicities in length spectra on the modular surface, and Lukianov ( Forum Math. 19 (2007) 851–903, http://www.math.tau.ac.il/~rudnick/students/lukianovthesis.pdf (Ph.D thesis version, Tel-Aviv University, 2005)) extended his asymptotic formula to the Riemann surfaces associated with the congruence subgroup 0 ( n ) or the quaternion-type co-compact arithmetic groups. The coefficients of the leading terms in these asymptotic formulas are described as Euler products over prime numbers, and they appear in eigenvalue statistic formulas of Rudnick ( Ann. Henri Poincaré 6 (2005) 863–883) and Lukianov ( Forum Math. 19 (2007) 851–903, http://www.math.tau.ac.il/~rudnick/students/lukianovthesis.pdf (Ph.D. thesis version, Tel-Aviv University, 2005)) for the Laplace–Beltrami operators on the corresponding Riemann surfaces. In the present paper, we further extend their asymptotic formulas to the higher level correlations of the multiplicities in the length spectra for any congruence subgroup of the modular group.
    Print ISSN: 0024-6093
    Electronic ISSN: 1469-2120
    Topics: Mathematics
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  • 7
    Publication Date: 2016-04-12
    Description: Background Antibody therapeutic targeting of the immune checkpoints cytotoxic T-lymphocyte-associated molecule 4 (CTLA-4) and programmed cell death 1 (PD-1) has demonstrated marked tumor regression in clinical trials. MicroRNAs (miRNAs) can modulate multiple gene transcripts including possibly more than one immune checkpoint and could be exploited as immune therapeutics. Methods Using online miRNA targeting prediction algorithms, we searched for miRNAs that were predicted to target both PD-1 and CTLA-4. MiR-138 emerged as a leading candidate. The effects of miR-138 on CTLA-4 and PD-1 expression and function in T cells were determined and the therapeutic effect of intravenous administration of miR-138 was investigated in both immune-competent and -incompetent murine models of GL261 glioma. Results Target binding algorithms predicted that miR-138 could bind the 3' untranslated regions of CTLA-4 and PD-1, which was confirmed with luciferase expression assays. Transfection of human CD4+ T cells with miR-138 suppressed expression of CTLA-4, PD-1, and Forkhead box protein 3 (FoxP3) in transfected human CD4+ T cells. In vivo miR-138 treatment of GL261 gliomas in immune-competent mice demonstrated marked tumor regression, a 43% increase in median survival time ( P = .011), and an associated decrease in intratumoral FoxP3+ regulatory T cells, CTLA-4, and PD-1 expression. This treatment effect was lost in nude immune-incompetent mice and with depletion of CD4+ or CD8+ T cells, and miR-138 had no suppressive effect on glioma cells when treated directly at physiological in vivo doses. Conclusions MiR-138 exerts anti-glioma efficacy by targeting immune checkpoints which may have rapid translational potential as a novel immunotherapeutic agent.
    Print ISSN: 1522-8517
    Electronic ISSN: 1523-5866
    Topics: Medicine
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  • 8
    Publication Date: 2016-07-30
    Description: Two transferrin (Tf) glycan-isoforms were previously found in cerebrospinal fluid (CSF); one appears to be derived from serum (Tf-2) and the other from choroid plexus, a CSF-producing tissue (Tf-1). To analyse metabolic differences associated with the two isoforms, their ratio (Tf-2/Tf-1) was defined as the Tf index. Here we report that Tf indices of patients with tauopathies including Alzheimer’s disease (2.29 + 0.64) were similar to those of neurological controls (2.07 + 0.87) ( P = 0.147). In contrast, Tf indices with Parkinson’s disease (PD, 3.38 ± 1.87) and multiple system atrophy (MSA, 3.15 ± 1.72) were higher than those of the controls (2.07 ± 0.87), the P -values being 〈 0.001 and 0.024, respectively. Tf indices of PD and MSA did not appear to be normally distributed. Indeed, detrended normal Quantile–Quantile plot analysis revealed the presence of an independent subgroup showing higher Tf indices in PD and MSA. The subgroup of PD showed higher levels of CSF α-synuclein (38.3 ± 17.8 ng/ml) than the rest (25.3 ± 11.3 ng/ml, P = 0.012). These results suggest that PD (and MSA) includes two subgroups, which show different metabolism of CSF transferrin and α-synuclein.
    Print ISSN: 0021-924X
    Electronic ISSN: 1756-2651
    Topics: Biology , Chemistry and Pharmacology
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  • 9
    Publication Date: 2014-04-02
    Description: We report a systematic multiwavelength investigation of environments of the brightest cluster galaxies (BCGs), using the X-ray data from the Chandra archive, and optical images taken with 34 27 arcmin 2 field-of-view Subaru Suprime-Cam. Our goal is to help understand the relationship between the BCGs and their host clusters, and between the BCGs and other galaxies, to eventually address a question of the formation and co-evolution of BCGs and the clusters. Our results include the following. (1) Morphological variety of BCGs, or the second or the third brightest galaxy (BCG2, BCG3), is comparable to that of other bright red sequence galaxies, suggesting that we have a continuous variation of morphology between BCGs, BCG2, and BCG3, rather than a sharp separation between the BCG and the rest of the bright galaxies. (2) The offset of the BCG position relative to the cluster centre is correlated to the degree of concentration of cluster X-ray morphology (Spearman  = –0.79), consistent with an interpretation that BCGs tend to be off-centred inside dynamically unsettled clusters. (3) Morphologically disturbed clusters tend to harbour the brighter BCGs, implying that the ‘early collapse’ may not be the only major mechanism to control the BCG formation and evolution.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
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  • 10
    Publication Date: 2016-10-08
    Description: Background Expression of programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) across glioma grades is undocumented, and their interactions with commonly expressed genetic and epigenetic alterations are undefined but nonetheless highly relevant to combinatorial treatments. Methods Patients with CNS malignancies were profiled by Caris Life Sciences from 2009 to 2016. Immunohistochemistry findings for PD-1 on tumor-infiltrating lymphocytes (TIL) and PD-L1 on tumor cells were available for 347 cases. Next-generation sequencing, pyrosequencing, immunohistochemistry, fragment analysis, and fluorescence in situ hybridization were used to determine isocitrate dehydrogenase 1 (IDH1), phosphatase and tensin homolog (PTEN), and tumor protein 53 mutational status, O 6 -DNA methylguanine-methyltransferase promoter methylation (MGMT-Me) status, PTEN expression, plus epidermal growth factor receptor variant III and 1p/19q codeletion status. Results PD-1+ TIL expression and grade IV gliomas were significantly positively correlated (odds ratio [OR]: 6.363; 95% CI: 1.263, 96.236)—especially in gliosarcomas compared with glioblastoma multiforme ( P = .014). PD-L1 expression was significantly correlated with tumor grade with all PD-L1+ cases ( n = 21) being associated with grade IV gliomas. PD-1+ TIL expression and PD-L1 expression were significantly correlated (OR: 5.209; 95% CI: 1.555, 20.144). Mutations of PTEN, tumor protein 53, BRAF, IDH1, and epidermal growth factor receptor or MGMT-Me did not associate with increased intratumoral expression of either PD-1+ TIL or PD-L1 in glioblastoma multiforme even before false discovery rate correction for multiple comparison. Conclusions Targeting immune checkpoints in combination with other therapeutics based on positive biomarker selection will require screening of large patient cohorts.
    Print ISSN: 1522-8517
    Electronic ISSN: 1523-5866
    Topics: Medicine
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