Biomedical subjects
Publications and source records attributed to T Yokoi.
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T lymphocytes from cord blood and adults stimulated with mitogens and alloantigen were analyzed using monoclonal antibodies that detect Ia and Tac antigens associated with lymphocyte activation. Less than 5% of T cells freshly isolated or cultured without stimuli expressed Ia and Tac antigens assessed by the indirect immunofluorescence method. When both T cells from cord blood and adults were cultured with phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), or allogeneic cells, variable proportions of them expressed Tac antigen. The expression of Tac antigen on stimulated T cells increased in parallel with DNA synthesis, and was significantly correlated with the proliferative response of stimulated T cells. In contrast to Tac antigen, the expression of Ia antigens appeared to show some time lag behind the proliferative response. Although expression of Ia antigens was too weak to assess in PHA- or Con A-stimulated cultures, adult T cells were stimulated by PWM or allogeneic cells to express strongly Ia antigens in culture. However, the percentage of Ia+ cells in cord blood T cells stimulated with PWM or allogeneic cells was markedly lower as compared with that of adults. In addition, cord blood T cells grown in the presence of T cell growth factor showed the same degree of Tac antigen as adult ones did, whereas their expression of Ia antigens was negligible as compared with adult controls. These observations suggested that T cells in cord blood might be deficient by nature in their ability to express Ia antigens on activation. The inability to develop Ia+ T cells seemed to be characteristic of functional immaturity of T cells in early human ontogeny.
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Urinary glycosaminoglycans were isolated with the cetylpyridinium chloride (CPC) precipitation method and the excretion of individual species of urinary glycosaminoglycans in three patients with Lowe's syndrome was compared with that of age-matched control children by means of electrophoresis on cellulose acetate membranes and by quantification of hexosamine contents. Total daily excretion of urinary glycosaminoglycans in the patients seemed to be normal, but the relative excretion of urinary heparan sulfate was significantly reduced and ranged from 26 to 46% of the age-matched control mean, when calculated on the basis of relative glucosamine content in urinary glycosaminoglycans. Although electrophoretograms of urines from patients with Lowe's syndrome suggested some excess of low sulfated chondroitin sulfate corresponding in mobility to dermatan sulfate, the enzymatic subunit assay employing chondroitinases did not disclose any significant differences in the excretion pattern or in the degree of sulfation of chondroitin sulfate isomers between lowe's syndrome and control children.
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A+ and A- rabbits were immunized with human A red cells, saliva of A+ or A- rabbits or human A.Se. A- rabbits responded well against A.Se saliva and A cells and slightly against A+ saliva, whereas A+ rabbits produced high-titered antibody against A cells which was abolished by absorption with O cells. Agglutination inhibition tests showed that anti-A from A- rabbits immunized with A.Se or A cells was not inhibited with A+ saliva, and anti-A from rabbits immunized with A cells was not absorbed with A.Se saliva. Hydroxylapatite chromatography separated each of A.Se and A+ saliva into three fractions of which the 1st and 3rd fractions of A.Se and only the 3rd of A+ had A activity. The 3rd fraction of A.Se and A+ did not inhibit anti-A from any rabbits immunized but the 1st of A.Se inhibited anti-A from all rabbits except for A+ immunized with A cells. The 1st and 2nd fractions reacted slightly with anti-A from A- immunized with A+ and from A+ immunized with A cells. D. biflorus anti-A distinguished human A from rabbit one but Mushroom anti-A could not. These results suggested qualitative differences between human and rabbit saliva A antigens.
Non-hemoglobin proteins (NHPs) of 12 species of mammalian were effectively isolated from red cell lysates with CM-Sephadex chromatography. Polyacrylamide gel disc electrophoresis demonstrated that human and monkey NHPs had 13 and 11 bands, respectively, but guinea pig and swine two to three bands. Rabbit anti-human NHP reacted with monkey, bovine, canine and badger as well as human. Absorption of the anti-NHP with monkey NHP resulted in preparing human specific anti-NHP. The specific antiserum gave two bands locating near the origin in immunoelectrophoresis. Human specific antigens were prepared by affinity chromatography with the anti-NHP. The antigens were composed of three bands, two of which had slightly faster mobility than carbonic anhydrase and the other migrated fastly on disc electrophoresis. These bands were proved to have neither LDH nor esterase activity.
Cell-free culture supernatants (Con A-activated supernatants) were obtained by incubating peripheral blood lymphocytes (PBL) from cord blood, healthy children of various ages, and healthy adults with mitogenic doses of concanavalin A (Con A) for 48 hr. It is well known that human T lymphocytes are activated by Con A to manifest suppressor function in vitro. One mechanism whereby these suppressor cells act has been shown to be by the secretion of a soluble suppressor factor. The present study has investigated the Con A-inducible suppressor cell function in cord blood, children of various ages, and adults by comparing the ability of each Con A-activated supernatant to inhibit the generation of immunoglobulin-producing cells (Ig-PC) in pokeweed mitogen- (PWM) stimulated cultures of adult PBL. Con A-activated supernatants from adults could markedly suppress the generation of Ig-PC by allogeneic as well as autologous PBL in response to PWM. Such suppression appeared to be equally effective on the generation of IG-PC of 3 major classes, IgG, IgM, and IgA. On the contrary, Con A-activated supernatants from cord blood and newborn infants showed only a negligible suppression on PWM-induced adult B cell differentiation. But the suppressor activity found in Con A-activated supernatants gradually increased with advancing age, and reached approximately to the adult level at 4 yr of age or later. The results suggest that human T lymphocytes may be relatively deficient in their Con A-induced suppressor cell function in the early period of life.
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Several lysosomal acid hydrolases were assayed in peripheral blood leukocytes from a patient with I-cell disease by the method of Hindman, J. and Cotlier, E. ((1972) Clin. Chem. 18, 971--975). The activities of lysosomal hydrolases in polymorphonuclear cells showed no significant differences between the patient, the parents, and normal controls, while lymphocytes from the patient exhibited the reduced activities of alpha- and beta-galactosidases, beta-glucuronidase, and N-acetyl-beta-glucosaminidase. After phytohemagglutinin-stimulated culture, lymphocytes from the patient showed a more definite reduction in the activities of these lysosomal enzymes; the activities of beta-glucuronidase, alpha-mannosidase, and N-acetyl-beta-glucosaminidase were reduced to about 20--30% of the activity in the phytohemagglutinin-stimulated control cultures, and the activities of alpha- and beta-galactosidases to 10% or less. Lymphocytes from the parents showed no significant difference in the activities of these enzymes from the controls, whether stimulated or not.
Analysis of the liberation degrees of intracellular materials from Ehrlich ascites tumor cells by treatment of Triton X-100 was performed. The liberation process has two stages. In the first stage, cytoplasmic inorganic phosphorus were liberated at a concentration of about 0.01% of the detergent, and in the second stage macromolecules such as lysosomal enzymes were liberated at a concentration of about 0.03% of the detergent. Morphologically, the cells began to swell in the first stage but were not stained by Trypan blue, and the cells in the second stage became fully swollen and ruptured. The staining curve of the swollen and ruptured cells was closely in parallel with the liberation curves of the macromolecules.
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