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Biomedical subjects

Y Komiyama

Publications and source records attributed to Y Komiyama.

At least 91 records · Page 5Linked to original sources

Determination of main inhibitor of activated factor XI.

To study the contribution of alpha 1 antitrypsin (alpha 1AT) and antithrombin III (AT III) to the inactivation of F.XIa in plasma, we developed the assay system of F.XIa-AT III complex according to our method of F.XIa-alpha 1AT complex, and measured the levels of both complexes in the patients with disseminated intravascular coagulation (DIC) derived from various triggers. F.XIa-alpha 1AT complex level was always higher than F.XIa-AT III complex level in each patient, independently on the trigger of DIC, the administration of heparin and the levels of F.XI, alpha 1AT and AT III. These results indicate that alpha 1AT is the main inhibitor of F.XIa in plasma.

Antithrombin III↗

Measurement of membrane fluidity of polymorphonuclear leukocytes by flow cytometry.

A method was established for measuring membrane fluidity of polymorphonuclear leukocytes (PMN) by the excimer-forming lipid technique with pyrenedecanoic acid in flow cytometry. When cells were labeled, the use of 2-25 microM of pyrenedecanoic acid provided similar results. Neither the removal of the unincorporated pyrenedecanoic acid nor adjustment of PMN counts exhibited any effect. By the gate analysis method, membrane fluidity of PMN could be measured with 100 microliters of heparinized whole blood in a short time and results with PMN in whole blood was similar to those with purified PMN. Therefore, purification and count adjustment of PMN could be omitted. By this method, membrane fluidity of PMN, which were treated with membrane fluidizer, was measured successfully. This method could be applied to the study of PMN function in various diseases.

Adult↗

Factor XIa-alpha 1 antitrypsin complex--elevation in the patients with DIC.

We developed an assay for the factor XIa-alpha 1 antitrypsin complex (F.XIa-alpha 1AT complex) in plasma. The purified factor XI (F.XI) activated with beta-XIIa and treated with alpha 1 antitrypsin (alpha 1 AT) served as the standard complex. The assay is an enzyme-linked differential antibody immunosorbent assay. The complex level of tested plasma was measured with peroxidase-labeled anti-alpha 1AT Fab' after the addition of 10-fold diluted test plasma (200 microliter) to the anti-F.XI monoclonal antibody beads. To eliminate the effects of plasma, the standard F.XIa-alpha 1AT complex was diluted with F.XI-deficient plasma (10-fold diluted) which did not contain the complex. Purified F.XI (0.08 micrograms/assay, i.e. 100%) was added to the standard F.XIa-alpha 1AT complex, because the absorbance of the standard complex containing F.XI (0.016-0.12 micrograms/assay, i.e. 20-150%) was a little lower than that of the complex alone. The recovery of the F.XIa-alpha 1AT complex added was over 90%. Neither F.XI nor alpha 1AT alone had the color development. The complex level of 25 normal individuals was below the detectable limit (less than 0.18 ng/assay), whereas the 30 patients with disseminated intravascular coagulation (DIC) had a high level complex (0.18-4.2 ng/assay). This assay may be helpful for the diagnosis of DIC.

Disseminated Intravascular Coagulation↗

Murine monoclonal antibodies to human factor XI.

Murine monoclonal antibodies to human factor XI (F.XI) are described. The monoclonal antibodies (2-1, 4-1, 7-1 and 10-1) consisted of IgG1. 4-1 inhibited the activation of F.XI completely in the presence of high molecular weight kininogen and kaolin and the others did so partially, whereas these antibodies had no effect on the activation of F.XI with activated factor XII (beta-XIIa). Four antibodies had no effect directly on the amidolytic activity of activated F.XI (F.XIa). 10-1 inhibited the activation of factor IX in coagulant assay for F.XIa by Mannhalter. And 4-1 and 7-1 did so partially, whereas 2-1 did not. In immunoblotting analysis, all antibodies bound to F.XI, its reduced form and F.XIa. All were directed against the heavy chain of F.XI. All antibodies recognized F.XIa-alpha 1 antitrypsin complex.

Antibodies, Monoclonal↗