Biomedical subjects

H Take

Publications and source records attributed to H Take.

At least 91 records · Page 5Linked to original sources

PubMed1989

New approach to eliminate HLA class I antigens from platelet surface without cell damage: acid treatment at pH 3.0.

A new method was studied for eliminating HLA class I antigens from the surface of platelets without damaging the cells. Platelets were exposed to an acid solution (pH 3.0) to eliminate the antigenicity of HLA class I antigens. The reduction in antigenicities of HLA class I common antigen and individual HLA class I antigens by acid treatment was marked. Patients' sera which contained multispecific HLA antibodies reacted with PBS-treated platelets, but not with acid-treated platelets. No changes were observed in the antigenicities of glycoprotein Ib or glycoprotein IIb/IIIa. The viability of acid-treated platelets was 83%. Ultrastructural investigations revealed no significant difference between the PBS-treated platelets and acid-treated platelets. The platelet function studies showed that the aggregation of acid-treated platelets induced by various agonists was only slightly reduced compared with PBS-treated platelets. We propose that acid-treated platelets are promising for clinical use in patients refractory to platelet transfusions and may be superior to chloroquine-treated platelets for analysis of the specificity of antiplatelet antibodies.

Blood Platelets↗

PubMed1989

[Comparative studies on an autoantigen in ITP and the Baka alloantigen on platelet membrane glycoprotein IIb].

Platelet membrane glycoprotein (GP) IIb carries not only the Baka alloantigen but also an autoantigen in some patients with chronic idiopathic thrombocytopenic purpura (ITP). We previously reported one ITP patient (RY) with anti-GPIIb autoantibody in her plasma. In this report, we investigated whether the epitope of the autoantigen on GPIIb (case RY) is identical to that of the Baka alloantigen or not. The anti-Baka antibody used in this study was obtained from a mother with a child suffering from neonatal alloimmune thrombocytopenic purpura as reported by Okada et al. Immunoblotting showed that the anti-Baka antibody bound to GPIIb from Baka-positive platelets only. In contrast, the anti-GPIIb autoantibody in RY plasma bound to GPIIb, irrespective of Baka phenotype. In addition, after neuraminidase treatment of GPIIb on nitrocellulose paper, the anti-Baka antibody failed to bind to Baka-positive GPIIb, while the autoantibody still bound to GPIIb. From these data, we conclude that the epitope of the autoantigen in RY patient is different from that of the Baka alloantigen.

Antigen-Antibody Reactions↗

PubMed1989

[Immunochemical characterization of platelet-specific alloantigen Baka].

We investigated the location of platelet-specific alloantigen Baka on platelet membrane glycoproteins. In indirect immunoprecipitation experiments, the anti-Baka antibody precipitated glycoprotein (GP) II b and a small amount of GP III a. The immunoblots using partially purified GP II b/III a complex as the target antigen indicated that GP II b alpha carried the Baka alloantigen. When the partially purified GP II b/III a complex digested with chymotrypsin was examined, the Baka alloantigen was found on a 65 kD fragment derived from GP II b alpha under reducing conditions. In addition, the immunoblots after two-dimensional nonreduced-reduced SDS-PAGE directly indicated that the 65 kD fragment had a mol. wt. of 80 kD under nonreducing conditions. The immunoblots using platelets digested in situ with chymotrypsin indicated that the 65 kD fragment of GP II b alpha was retained by the platelet membrane. We conclude, therefore, that the Baka alloantigen is located on a 65 kD fragment that represents the membrane side of the cleavage site of chymotrypsin on GP II b alpha.

Antigens, Human Platelet↗

PubMed1988

Classification of chronic granulomatous disease on the basis of monoclonal antibody-defined surface cytochrome b deficiency.

Flow cytometric quantitative analysis of cytochrome b on outer surface membrane and of oxidative product formation in polymorphonuclear leukocytes (PMNLs) from patients with chronic granulomatous disease was carried out with the use of monoclonal antibody against cytochrome b of human neutrophils and 2', 7'-dichlorofluorescin diacetate. Cytochrome b was present on the outer surface membrane of PMNLs in normal individuals, and its absence on the outer surface membrane was of value in the diagnosis and classification of chronic granulomatous disease. This study has shown that a major type of chronic granulomatous disease is one of the monoclonal antibody-defined surface membrane diseases.

Adolescent↗

PubMed1979