Publications by authors named "Youichi Takahama"

Aberrant glycosylation of IgA1 is involved in the development of IgA nephropathy (IgAN). There are many reports of IgAN markers focusing on the glycoform of IgA1. None have been clinically applied as a routine test.

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Background: Aberrant glycosylation has been reported to play important roles in progression of cholangiocarcinoma (CCA) and hence the aberrant expressed glycans are beneficial markers for diagnosis and prognostic prediction of CCA.

Methods: Five CCA-associated glycobiomarkers-carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen-S27 (CA-S27), CCA-associated carbohydrate antigen (CCA-CA), WFA-positive MUC1 (WFA-MUC1), and WFA-positive M2BP (WFA-M2BP), in the sera from CCA patients (N = 138) were determined in comparison with non-CCA control subjects (N = 246).

Results: Receiver operating characteristic analysis suggested the significance of each glycobiomarker in discriminating CCA from non-CCA with area under curve of 0.

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Anti-retroviral therapy is useful to treat human immunodeficiency virus type 1 (HIV-1)-infected individuals, but has some major problems, such as the generation of multidrug-resistant viruses. To develop a novel supplemental or alternative therapeutic for CCR5-tropic (R5) HIV-1 infection, we generated a recombinant vesicular stomatitis virus (rVSV) in which the gene encoding its envelope glycoprotein (G) was replaced with the genes encoding R5 HIV-1 receptors (human CD4 and CCR5), designated VSVΔG-CC5. Our present data demonstrate that this rVSV specifically infects cells that are transiently expressing R5 HIV-1 envelope glycoproteins, but does not infect those expressing CXCR4-tropic HIV-1 envelope glycoproteins.

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Article Synopsis
  • Researchers created a new recombinant vesicular stomatitis virus (rVSV) that expresses the hepatitis C virus (HCV) proteins E1 and E2, along with a green fluorescent protein (GFP), to study HCV more effectively.
  • This new VSV/HCV was able to infect human liver cancer cells (Huh7), express GFP, and replicate, but it did not infect other types of cells, like BHK-21.
  • The study found that the addition of certain antibodies or serum from HCV-infected patients reduced infection, suggesting this rVSV could help explore how HCV enters cells and test potential antiviral treatments.
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Purpose: Wisteria floribunda agglutinin positive human Mac-2-binding protein (WFA(+)-hM2BP) was recently validated as a liver fibrosis glycobiomarker with a fully automated lectin-antibody sandwich immunoassay. In this study, we supplied recombinant WFA(+)-hM2BP as the standard glycoprotein and the overlaid antibody to enhance the robustness of WFA(+)-hM2BP quantification.

Experimental Design: The optimum conditions for producing recombinant WFA(+)-hM2BP were selected by cell glycome analysis based on a lectin microarray.

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Background: A quantitative analysis of glyco-alteration in serum glycoproteins provides glyco-parameters for estimating the progression of liver fibrosis. In the analysis of glycans, a manual pretreatment process for clinical specimens leads to a complicated manipulation and loss-of-clinical implementation of the assay.

Method: We evaluated an automated triplex lectin-antibody sandwich immunoassay assisted by an automated protein purification system (ED-01) and a bedside clinical chemistry analyzer (HISCL) for the acquisition of two glyco-parameters (AOL/DSA and MAL/DSA) derived from a fibrosis-related glyco-alteration of serum alpha1-acid glycoprotein (AGP).

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Human immunodeficiency virus type 1 (HIV-1) utilizes a highly complex splice site regulation system, taking advantage of host proteins, to express its own viral protein in an orderly way. We show here that one of the host proteins, high mobility group A protein 1a (HMGA1a), is involved in splice site regulation of 3' splice site 2 (A2) and 5'splice site 3 (D3) of HIV-1 genomic RNA. shRNA knockdown of HMGA1 in HeLa cells resulting in a decrease of HMGA1 showed a significant decrease of Vpr mRNA.

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OX40 protein is highly expressed on activated CD4-positive T cells that are susceptible for human immunodeficiency virus type 1 (HIV-1) infection. To target and kill HIV-1-infected OX40(+) T cells, we used a recombinant vesicular stomatitis virus (rVSV) lacking its envelope glycoprotein (ΔG) and instead expressing HIV-1 receptors CD4/CXCR4 and OX40 ligand (OX40L). Expression of OX40L as well as HIV-1 receptors on the VSV particles led to specific infection of OX40(+) T cells, including primary cells, either acutely or chronically infected with X4 HIV-1.

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