173 research outputs found

    Application of Long-Range Surface Plasmon Resonance for ABO Blood Typing

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    In this study, we demonstrate a long-range surface plasmon resonance (LR-SPR) biosensor for the detection of whole cell by captured antigens A and B on the surface of red blood cells (RBCs) as a model. The LR-SPR sensor chip consists of high-refractive index glass, a Cytop film layer, and a thin gold (Au) film, which makes the evanescent field intensity and the penetration depth longer than conventional SPR. Therefore, the LR-SPR biosensor has improved capability for detecting large analytes, such as RBCs. The antibodies specific to blood group A and group B (Anti-A and Anti-B) are covalently immobilized on a grafting self-assembled monolayer (SAM)/Au surface on the biosensor. For blood typing, RBC samples can be detected by the LR-SPR biosensor through a change in the refractive index. We determined that the results of blood typing using the LR-SPR biosensor are consistent with the results obtained from the agglutination test. We obtained the lowest detection limits of 1.58 × 105 cells/ml for RBC-A and 3.83 × 105 cells/ml for RBC-B, indicating that the LR-SPR chip has a higher sensitivity than conventional SPR biosensors (3.3 × 108 cells/ml). The surface of the biosensor can be efficiently regenerated using 20 mM NaOH. In summary, as the LR-SPR technique is sensitive and has a simple experimental setup, it can easily be applied for ABO blood group typing

    Density of the Notch ligand Delta1 determines generation of B and T cell precursors from hematopoietic stem cells

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    Notch signaling regulates multiple cell fate decisions by hematopoietic precursors. To address whether different amounts of Notch ligand influence lineage choices, we cultured murine bone marrow lin−Sca-1+c-kit+ cells with increasing densities of immobilized Delta1ext-IgG consisting of the extracellular domain of Delta1 fused to the Fc domain of human IgG1. We found that relatively lower densities of Delta1ext-IgG enhanced the generation of Sca-1+c-kit+ cells, Thy1+CD25+ early T cell precursors, and B220+CD43−/lo cells that, when cocultured with OP9 stroma cells, differentiated into CD19+ early B cell precursors. Higher densities of Delta1ext-IgG also enhanced the generation of Sca-1+c-kit+ precursor cells and promoted the development of Thy1+CD25+ cells, but inhibited the development of B220+CD43−/lo cells. Analyses of further isolated precursor populations suggested that the enhanced generation of T and B cell precursors resulted from the effects on multipotent rather than lymphoid-committed precursors. The results demonstrate the density-dependent effects of Delta1 on fate decisions of hematopoietic precursors at multiple maturational stages and substantiate the previously unrecognized ability of Delta1 to enhance the development of both early B and T precursor cells

    Radioligand Assay-Based Detection of Antibodies against SARS-CoV-2 in Hospital Workers Treating Patients with Severe COVID-19 in Japan.

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    This study aimed to clarify whether infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is prevalent among the staff of a hospital providing treatment to patients with severe coronavirus disease 2019 (COVID-19) using radioligand assay (RLA). One thousand samples from the staff of a general hospital providing treatment to patients with severe COVID-19 were assayed for SARS-CoV-2 nucleocapsid protein (N) IgG using RLA. Nine patients with COVID-19 who had been treated in inpatient settings and had already recovered were used as control subjects, and 186 blood donor samples obtained more than 10 years ago were used as negative controls. Four of the 1000 samples showed apparently positive results, and approximately 10 or more samples showed slightly high counts. Interestingly, a few among the blood donor samples also showed slightly high values. To validate the results, antibody examinations using ELISA and neutralizing antibody tests were performed on 21 samples, and chemiluminescence immunoassay (CLIA) was performed on 201 samples, both resulting in a very high correlation. One blood donor sample showed slightly positive results in both RLA and CLIA, suggesting a cross-reaction. This study showed that five months after the pandemic began in Japan, the staff of a general hospital with a tertiary emergency medical facility had an extremely low seroprevalence of the antibodies against SARS-CoV-2. Further investigation will be needed to determine whether the slightly high results were due to cross-reactions or a low titer of anti-SARS-CoV-2 antibodies. The quantitative RLA was considered sensitive enough to detect low titers of antibodies

    Legionella pneumophila in Rainwater on Roads

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    During rain, transient puddles form on roads, and this water is splashed into the air by moving vehicles. To determine whether this water contains Legionella pneumophila, we collected samples from roads. We found that L. pneumophila are abundant in these puddles, especially during warm weather

    Genetic Reprogramming With Stem Cells Regenerates Glomerular Epithelial Podocytes in Alport Syndrome

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    Glomerular filtration relies on the type IV collagen (ColIV) network of the glomerular basement membrane, namely, in the triple helical molecules containing the α3, α4, and α5 chains of ColIV. Loss of function mutations in the genes encoding these chains (Col4a3, Col4a4, and Col4a5) is associated with the loss of renal function observed in Alport syndrome (AS). Precise understanding of the cellular basis for the patho-mechanism remains unknown and a specific therapy for this disease does not currently exist. Here, we generated a novel allele for the conditional deletion of Col4a3 in different glomerular cell types in mice. We found that podocytes specifically generate α3 chains in the developing glomerular basement membrane, and that its absence is sufficient to impair glomerular filtration as seen in AS. Next, we show that horizontal gene transfer, enhanced by TGFβ1 and using allogenic bone marrow-derived mesenchymal stem cells and induced pluripotent stem cells, rescues Col4a3 expression and revive kidney function in Col4a3-deficient AS mice. Our proof-of-concept study supports that horizontal gene transfer such as cell fusion enables cell-based therapy in Alport syndrome

    Risk-adjusted therapy for pediatric non-T cell ALL improves outcomes for standard risk patients: results of JACLS ALL-02

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    This study was a second multicenter trial on childhood ALL by the Japan Childhood Leukemia Study Group (JACLS) to improve outcomes in non-T ALL. Between April 2002 and March 2008, 1138 children with non-T ALL were enrolled in the JACLS ALL-02 trial. Patients were stratified into three groups using age, white blood cell count, unfavorable genetic abnormalities, and treatment response: standard risk (SR), high risk (HR), and extremely high risk (ER). Prophylactic cranial radiation therapy (PCRT) was abolished except for CNS leukemia. Four-year event-free survival (4yr-EFS) and 4-year overall survival (4yr-OS) rates for all patients were 85.4% ± 1.1% and 91.2% ± 0.9%, respectively. Risk-adjusted therapy resulted in 4yr-EFS rates of 90.4% ± 1.4% for SR, 84.9% ± 1.6% for HR, and 66.5% ± 4.0% for ER. Based on NCI risk classification, 4yr-EFS rates were 88.2% in NCI-SR and 76.4% in NCI-HR patients, respectively. Compared to previous trial ALL-97, 4yr-EFS of NCI-SR patients was significantly improved (88.2% vs 81.2%, log rank p = 0.0004). The 4-year cumulative incidence of isolated (0.9%) and total (1.5%) CNS relapse were significantly lower than those reported previously. In conclusion, improved EFS in NCI-SR patients and abolish of PCRT was achieved in ALL-02

    e-Learningにおけるポートフォリオ評価法の動向とその応用

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    本研究の目的は、ポートフォリオ評価法の理論的枠組みと、ポートフォリオ評価法をe-Learningに導入した研究の知見を概観し、ポートフォリオ評価法を応用したe-Learning環境のデザインについて考察することにある。ポートフォリオ評価法の研究は勃興期に位置づけられる。多くの研究が学習者中心型アプローチの立場から、ポートフォリオ評価法をe-Learning環境に導入するフレームワークを検討し、一部の研究はその効果を検証している段階にある。ポートフォリオを作成することや、そのための支援ツールの実装に注目が集まっている。ポートフォリオ評価法の理念に立ち返れば、学習者と熟達者間、あるいは学習者相互によるポートフォリオの検討やその評価、学習活動の改善に向けた内省や計画立案といった学習活動を行うためのコミュニケーション環境を充実させることが重要である。また、様々な学習方法に対応して、その学習プロセスに対する内省を促進するようなポートフォリオ作成を支援することが、e-Leamingにおける学習環境デザインに必要である。The aim of this paper is to examine the design of learning environments involving portfolio assessment applied in e-learning with recent studies and frameworks. Research in this field is largely in its early stages, and the study of schemes for utilizing portfolio assessment for e-learning takes the learner-centered approach. Some studies have made progress by taking account of new frameworks for portfolio utilization. The authors examine the appropriate learning environments for e-learning using portfolio assessment from the viewpoint of assessment theory and philosophy. In conclusion, an adequate communication environment between learners and experts is required for the promotion of learning. Such communication includes portfolio conferences, evaluation of learner portfolios and reflective planning for learning improvement. The design of portfolios appropriate to the instructional design is also needed in order to promote learner awareness of the learning process

    Keto form of curcumin derivatives strongly binds to Aβ oligomers but not fibrils.

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    The accumulation of β-amyloid (Aβ) aggregates in the brain occurs early in the progression of Alzheimer\u27s disease (AD), and non-fibrillar soluble Aβ oligomers are particularly neurotoxic. During binding to Aβ fibrils, curcumin, which can exist in an equilibrium state between its keto and enol tautomers, exists predominantly in the enol form, and binding activity of the keto form to Aβ fibrils is much weaker. Here we described the strong binding activity the keto form of curcumin derivative Shiga-Y51 shows for Aβ oligomers and its scant affinity for Aβ fibrils. Furthermore, with imaging mass spectrometry we revealed the blood-brain barrier permeability of Shiga-Y51 and its accumulation in the cerebral cortex and the hippocampus, where Aβ oligomers were mainly localized, in a mouse model of AD. The keto form of curcumin derivatives like Shiga-Y51 could be promising seed compounds to develop imaging probes and therapeutic agents targeting Aβ oligomers in the brain
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