30 research outputs found

    Single-molecule analysis of intracellular insulin granule behavior and its application to analyzing cytoskeletal dependence and pathophysiological implications

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    Introduction: Mobilization of intracellular insulin granules to the plasma membrane plays a crucial role in regulating insulin secretion. However, the regulatory mechanisms of this mobilization process have been poorly understood due to technical limitations. In this study, we propose a convenient approach for assessing intracellular insulin granule behavior based on single-molecule analysis of insulin granule membrane proteins labeled with Quantum dot fluorescent nanocrystals.Methods: This approach allows us to analyze intracellular insulin granule movement with subpixel accuracy at 33 fps. We tracked two insulin granule membrane proteins, phogrin and zinc transporter 8, fused to HaloTag in rat insulinoma INS-1 cells and, by evaluating the tracks with mean-square displacement, demonstrated the characteristic behavior of insulin granules.Results and discussion: Pharmacological perturbations of microtubules and F-actin affected insulin granule behavior on distinct modalities. Specifically, microtubule dynamics and F-actin positively and negatively regulate insulin granule behavior, respectively, presumably by modulating each different behavioral mode. Furthermore, we observed impaired insulin granule behavior and cytoskeletal architecture under chronic treatment of high concentrations of glucose and palmitate. Our approach provides detailed information regarding intracellular insulin granule mobilization and its pathophysiological implications. This study sheds new light on the regulatory mechanisms of intracellular insulin granule mobilization and has important implications for understanding the pathogenesis of diabetes

    Development of a quantitative prediction model for peripheral blood stem cell collection yield in the plerixafor era

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    BACKGROUND AIMS: Predicting autologous peripheral blood stem cell (PBSC) collection yield before leukapheresis is important for optimizing PBSC mobilization and autologous stem cell transplantation (ASCT) for treating hematological malignancies. Although guidelines for plerixafor usage based on peripheral blood CD34+ (PB-CD34+) cell count are available, their predictive performance in the real world remains unclear. METHODS: This study retrospectively analyzed 55 mobilization procedures for patients with non-Hodgkin lymphoma or multiple myeloma and developed a novel quantitative prediction model for CD34+ cell collection yield that incorporated four clinical parameters available the day before leukapheresis; namely, PB-CD34+ cell count the day before apheresis (day -1 PB-CD34+), number of prior chemotherapy regimens, disease status at apheresis and mobilization protocol. RESULTS: The effects of PB-CD34+ cell counts on CD34+ cell collection yield varied widely per patient characteristics, and plerixafor usage was recommended in patients with poorly controlled disease or those with a history of heavy pre-treatments even with abundant day -1 PB-CD34+ cell count. This model suggested a more proactive use of plerixafor than that recommended by the guidelines for patients with poor pre-collection condition or those with a higher target number of CD34+ cells. Further, the authors analyzed the clinical outcomes of ASCT and found that plerixafor use for stem cell mobilization did not affect short- or long-term outcomes after ASCT. CONCLUSIONS: Although external validations are necessary, the results can be beneficial for establishing more effective and safer mobilization strategies

    Prognostic impact of complex and/or monosomal karyotypes in post‐transplant poor cytogenetic acute myeloid leukaemia: A quantitative approach

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    To evaluate the prognostic impact of complex karyotype (CK) and/or monosomal karyotype (MK) in combination with various clinical factors on allogeneic stem cell transplantation (HSCT) outcomes of patients with acute myeloid leukaemia (AML), we analysed the registry database of adult AML patients who underwent allogeneic HSCT between 2000 and 2019 in Japan. Among 16 094 patients, those with poor cytogenetic risk (N = 3345) showed poor overall survival (OS) after HSCT (25.3% at 5 years). Multivariate analyses revealed that CK and/or MK (hazard ratio [HR], 1.31 for CK without MK; 1.27 for MK without CK; and 1.73 for both), age at HSCT ≥50 years (HR, 1.58), male sex (HR, 1.40), performance status ≥2 (HR, 1.89), HCT-CI score ≥3 (HR, 1.23), non-remission status at HSCT (HR, 2.49), and time from diagnosis to HSCT ≥3 months (HR, 1.24) independently reduced post-HSCT OS among patients with poor cytogenetic risk AML. A risk scoring system based on the multivariate analysis successfully stratified patients into five distinct groups for OS. This study confirms the negative effects of CK and MK on post-HSCT outcomes, and offers a powerful risk scoring system for predicting prognoses after HSCT among AML patients with unfavourable cytogenetics

    Case of plasmablastic lymphoma of the sigmoid colon and literature review

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    Plasmablastic lymphoma (PBL) is a rare form of non-Hodgkin\u27s lymphoma that is associated with human immunodeficiency virus (HIV) infection. Although PBL is most commonly observed in the oral cavity of HIV-positive patients, it can also be observed at extra-oral sites in HIV-negative patients. This report represents an unusual case of HIV-negative PBL that occurred in the sigmoid colon. This patient had a history of systemic lupus erythematosus and an underlying immunosuppressive state from long term steroid therapy. The lymphoma cells were positive for CD138, kappa light chain restriction and Epstein-Barr virus and negative for CD20/L26, CD3, CD79a, UCHL1 (CD45RO) and cytokeratin (AE1/AE3). The patient died approximately 2 mo after the operation. In the present paper, we review cases of PBL of the colon in HIVnegative patients

    Efficacy of Serotonin Type 3 Receptor Antagonist Ramosetron on Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D)-Like Symptoms in Patients with Quiescent Inflammatory Bowel Disease: A Randomized, Double-Blind, Placebo-Controlled Trial

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    Patients with quiescent inflammatory bowel disease (IBD) frequently suffer diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms, such as abdominal pain or stool irregularities. Here, we assessed the effect of ramosetron, a serotonin type 3 (5-HT3) receptor antagonist, on IBS-D-like symptoms in patients with quiescent IBD. Seventy patients with quiescent IBD, who met the Rome III diagnostic criteria for IBS-D, were randomly assigned to receive either ramosetron (5 μg; n = 35) or a placebo (n = 35) orally once daily for 4 weeks. The primary endpoint was the responder rate for global assessment of relief from overall IBS-D-like symptoms. The responder rates for relief of abdominal pain/discomfort and improvement of bowel habits were also evaluated. The responder rate for relief from overall IBS-D-like symptoms at the final evaluation point was significantly higher in the ramosetron group (35.5%) than in the placebo group (11.4%) (p = 0.037). The responder rate for improvement of bowel habits was significantly higher in the ramosetron group (38.7%) than in the placebo group (14.3%) (p = 0.028). The reduction of stool frequency was significantly greater in the ramosetron group than in the placebo group (p = 0.044). Ramosetron is effective for relief of overall IBS-D-like symptoms in patients with quiescent IBD
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