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Biomedical subjects

Kazuhiko Matsuno

Publications and source records attributed to Kazuhiko Matsuno.

10 recordsLinked to original sources

WAVE/Scars in platelets.

Using specific antibodies against isoforms of WAVE (WASP [Wiskott-Aldrich syndrome protein] family Verprolin-homologous protein, also called Scar), we demonstrated that human platelets express all 3 isoforms. With the use of an in vitro pull-down technique, the src homology 3 (SH3) domain of insulin receptor substrate p53 (IRSp53) precipitated WAVE2 from platelet lysates more efficiently than did profilin I. The opposite was true for WAVE1, and neither precipitated WAVE3, suggesting that WAVE isoforms have different affinities to these ligands, while the SH3 domain of abl binds to all 3 isoforms. The 3 WAVE isoforms were distributed in the actin-rich Triton X-100-insoluble pellets following platelet aggregation induced by thrombin receptor-activating peptide. We also found that all 3 WAVE isoforms are substrates for calpain in vivo and in vitro. Although portions of these 3 isoforms were commonly distributed in the actin- and actin-related protein 2 and 3 (Arp2/3)-rich edge of the lamellipodia in spreading platelets, only WAVE2 remained in the cell fringe following detergent extraction or fixation of the cells. Finally, by mass spectrometry, we found that the proteins, which reportedly interact with WAVE/Scars, are present in platelets. These data suggest that the 3 WAVE isoforms exhibit common and distinct features and may potentially be involved in the regulation of actin cytoskeleton in platelets.

Actin Cytoskeleton↗

CrkL directs ASAP1 to peripheral focal adhesions.

Searching for proteins in platelets that can interact with the N-terminal SH3 domain of CrkL (using a combination of a pull-down assay followed by mass spectrometry), we have found that human platelets express an ADP-ribosylation factor (Arf)-specific GTPase-activating protein (GAP), ASAP1, as a CrkL-binding protein. In spreading platelets, most endogenous ASAP1 is localized at peripheral focal adhesions. To determine the physiologic significance of the CrkL-ASAP1 association, we overexpressed CrkL, ASAP1, or both in combination in COS7 cells. Unlike endogenous ASAP1 in platelets, overexpressed ASAP1 showed diffuse cytoplasmic distribution. However, when co-expressed with wild-type CrkL, both endogenous and expressed ASAP1 accumulated at CrkL-induced focal adhesions. An SH2-mutated CrkL, which cannot localize at focal adhesions, failed to recruit ASAP1 into focal adhesions. Thus, CrkL appears to be a lynchpin between ASAP1 and peripheral focal adhesions.

Adaptor Proteins, Signal Transducing↗

Influence of low- and high-molecular-weight plasminogen activators on the onset of labor and on the hemostatic system.

Measurement of activities of urinary (u-PA) and tissue plasminogen activator (t-PA) and analysis of euglobulin lysis times (ELTs) and prekallikrein were performed simultaneously using the plasma of normal pregnant women and nonpregnant women. The activities of plasminogen activators were determined by the method of electrophoretic zymography. The activity of low-molecular-weight (LMW) u-PA was significantly decreased at the onset of labor (p = 0.05) compared with that during the latter half of pregnancy. The same tendency was observed in the analysis of prekallikrein. On the contrary, no significance was shown in activities of high-molecular-weight (HMW) u-PA or t-PA. It is suggested that the action of kallikrein on low-molecular-weight u-PA causes it to change into plasmin at the onset of labor.

Case-Control Studies↗

[Tumor producing amylase].

The phenotype of tumor-producing amylase is usually salivary-type amylase, in contrast, we experienced sialyl salivary-type amylase detected in the sera of the patients with malignancies. Sialyl salivary-type amylase, with an abnormal anodic migration, was detected by isoamylase electrophoretic analysis in the sera of patients with multiple myeloma and with ovarian cancer. The abnormal isoamylase bands migrated toward the anode faster than the salivary isoamylase band(S2) and were stained more strongly than S2 band. The isoamylases could be separated from residual normal isoamylases in the sera of patients by using gel permeation chromatography. The isoamylases were showed sensitive by neuraminidase treatment and were reacted with anti-human salivary monoclonal antibody.

Aged↗

Evaluation of hematological values obtained with reference automated hematology analyzers of six manufacturers.

We evaluated assays of the same fresh blood samples with six different types of reference automated hematology analyzers developed by the following manufacturers: Beckman Coulter, Sysmex, Bayer, Abbott, Nihon Kohden and Horiba. Fresh whole blood samples treated with dipotassium ethylenediaminetetraacetic acid (EDTA K2) were collected from three healthy adult volunteers. The complete blood counts (CBC) including red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct), mean corpuscular volume (MCV), white blood cell count (WBC), platelet count (Plt), reticulocyte percentage (Ret) and leukocyte differential counts including % neutrophils (Neu), % lymphocytes (Lym) and % monocytes (Mon) were surveyed with a reference automated hematology analyzer from each manufacturer. The process from sampling to analysis was performed according to procedures in hospital clinical laboratories. RBC, Hgb, Hct and MCV exhibited allowable differences within 5% of mean value among all instruments. Large differences greater than 10% of mean value in WBC, Neu and Lym between Horiba and other manufacturers, and in Plt between Nihon Kohden and other manufacturers, were observed. Ret and Mon exhibited large differences over 10% of mean value among almost all of the instruments tested. This survey suggests that all parameters exhibiting differences greater than 10% of mean value among instruments should be improved for clinical use to ensure good external quality control in blood cell counting and leukocyte differential counting using automated instruments.

Blood Cell Count↗

Quality control and quality assessment of coagulation tests in Japan.

We have used prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and fibronogen/fibrin degradation products (FDP) as screening coagulation tests, and antithrombin III (AT III), plasminogen (Plg), alpha2-plasmin inhibitor (alpha2-PI), protein C (PC), thrombin-AT III complex (TAT), plasmin-alpha2-PI complex (PIC), and D-dimer as special coagulation tests. We report the present condition of internal and external quality control for these coagulation tests in Japan. We made a summary report of internal quality control of some coagulation tests in Division of Hematology Laboratory, Department of Laboratory Medicine, Hokkaido University Hospital. The repeatability and reproducibility of screening tests were good, but those of special tests were partly adequate. We have participated in some external quality control surveillance including Japan Medical Association (JMA), Japanese Association of Laboratory Medical Technologists (JALMT), College of American Pathologists (CAP), and some commercial quality control surveillance. We also reported the results of some external quality control surveillance.

Blood Coagulation Tests↗