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S Shichijo

Publications and source records attributed to S Shichijo.

At least 73 records · Page 4Linked to original sources
PubMed1989

Monoclonal antibody to phospholamban isolated from bovine cardiac muscle.

Phospholamban, a putative protein regulator of the Ca2(+)-dependent ATPase in cardiac sarcoplasmic reticulum, was isolated from bovine cardiac microsomes using a low concentration of the detergent. The phospholamban was phosphorylated by cyclic AMP-dependent protein kinase to a level of 7.55 nmol of phosphate per mg of protein. This molecular weight was found to be 20,000 dalton based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Monoclonal antibody against the bovine phospholamban was made by the hybridoma technique. The specificity of the monoclonal antibody was determined by immunoblotting experiments and the antibody was shown capable of blocking the phosphorylation of phospholamban by cyclic AMP-dependent protein kinase. The immunoglobulin subclass of the antibody was identified as IgG1. The distribution of phospholamban in muscular tissues was observed by the immunohistological method and the results showed that myocardial cells were strongly and specifically stained, while skeletal and smooth muscle cells were stained at the background level. The results showed the phospholamban in the ventricular muscle to be localized along the cellular surface and in a network over the myofilaments. The monoclonal antibody identified a reactive component in the myocardial cells of monkey, canine, mouse and man.

Animals↗
PubMed1989

[Effect of salazosulfapyridine and its metabolites on immunocompetent cells].

Long-term administration of SASP does offer clinical benefit and has a demonstrable disease modifying effect in rheumatoid arthritis, though its mode of action remains obscure. We have studied the in vitro effects of SASP and its metabolites, that is SP, ASA, AcSP and AcASA, on the blast-formation of lymphocytes, the cytotoxic activity of NK cell, the phagocytosis and H2O2 production of monocyte and the fMLP-induced chemotaxis and superoxide anions production of PMNs. We have obtained the following results: (1) the blast-formation of lymphocytes by PHA and Protein A was significantly inhibited by SASP, but not by the metabolites; (2) the cytotoxic activity of the NK cell was inhibited by SP and AcSP, but not by SASP, ASA and AcASA; (3) on monocyte, SP, AcSP and AcASA inhibited phagocytosis, and all of drugs had no effect on the production of H2O2; (4) on PMNs, SASP, SP and ASA significantly inhibited fMLP-induced chemotaxis, and SASP and all of its metabolites significantly inhibited a release of superoxide anions by stimulation of fMLP and PMA; (5) SASP and ASA scavenged superoxide radical at the concentration comparable to clinical doses. In vivo, the above effects may be exhibited in proportion to each blood concentrations of drugs. In particular, it appears that SASP, SP and AcSP play an important role in the therapeutic efficacy in rheumatoid arthritis.

Chemotaxis, Leukocyte↗
PubMed1988

Human polymorphonuclear leukocyte activating factor isolated from Aleurites Fordii Hemsl. (Euphorbiaceae) seed.

A human polymorphonuclear leukocyte (PMN) activating factor (AFH-S) was isolated from a tropical plant seed, Aleurites Fordii Hemsl. (AFH) in PBS. It is found that the AFH-S stimulate human PMNs and induced superoxide generation and chemotaxis. Superoxide generation was affected by the extracellular calcium ion or pretreatment with H-7 (PK-C inhibitor), but not by mepacrine (PLA2 inhibitor) or pertussis toxin (islet-activating protein: IAP). Furthermore, a lag time exists dose-dependently. In addition the cytosolic calcium was not increased by the stimulation with AFH-S. Thus, the receptor for AFH-S was suggested to be independent from Ni-like protein, PI-response, or PLA2-activation, and stimulate PMNs through activation of PK-C.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1987

Differentiation-associated carbohydrate chain on human hematopoietic cells recognized by Clerodendron trichotomum lectin.

In the screening of hematopoietic cell line cell aggregations, the extract of Clerodendron trichotomum seed was found to aggregate K-562 and KG-1 specifically. In the flow cytometric analysis using FITC-conjugated purified CTL, it was confirmed that CTL recognizes the specific carbohydrate(s) which seem to appear only in the early stages of differentiation of myeloid (KG-1) and erythroid (K-562) cell line cells and erythrocytes. The CTL binding to K-562 cells was decreased by TPA treatment which is known to induce retrodifferentiation of K-562. It is also found that this carbohydrate(s) were shaded with NANA on the differentiated cells. In the erythrocyte, CTL receptor was partially shaded by NANA.

Carbohydrate Metabolism↗
PubMed1986

Inhibitory effects of gangliosides on immune reactions of antibodies to neutral glycolipids in liposomes.

Specific immune damage to liposomes containing Forssman or globoside glycolipid was inhibited when the liposomes also contained ganglioside. The activity of a human monoclonal Waldenström macroglobulin antibody to Forssman glycolipid was inhibited by each of three gangliosides tested, GM3, GD1a and GD1b. Inhibition of the monoclonal antibody was dependent on the amount of ganglioside in the liposomes, and was diminished by reducing the relative amount of ganglioside. Inhibition also correlated positively with the number of ganglioside sialic acid groups, with inhibition by GT1b greater than GD1a greater than GM3. Naturally occurring human antibodies to globoside glycolipid were detected in 18% (9 out of 50) of normal human sera tested. Immune damage to liposomes induced by each of the three highest-reacting human anti-globoside sera was blocked by liposomal GM3. We conclude that gangliosides can strongly influence immune damage to membranes induced by antibody interactions with adjacent neutral glycolipids.

Antibodies, Monoclonal↗
PubMed1985

Complement-dependent immune damage to liposomes containing gangliosides.

Rabbit antiserum against mixed beef brain gangliosides served as an excellent source of antibodies to gangliosides GM1, GM3, GD1a, GD1b, and GT1b. Immune potency of antiserum was determined by complement-dependent damage to liposomes containing gangliosides as antigens. Antibody levels in antiserum to mixed gangliosides, when tested against individual gangliosides, were equivalent or superior to the levels obtained by immunization of rabbits with purified individual gangliosides. Naturally occurring antibodies to GM1, GD1b, and GM3 were observed in preimmunization sera. The levels of these natural antibodies, although easily high enough to serve as antiserum sources for liposome assay, were increased substantially following immunization. High titers of antibodies to GM1 and GD1b were observed in certain individual guinea pig sera, and selection of individual non-reacting guinea pig sera was necessary in order to obtain suitable complement sources when testing rabbit antibodies to liposomal GM1 and GD1b. The maximum plateau level of trapped glucose release from liposomes in the presence of saturating levels of antigen, antiserum, and complement was influenced strongly both by the method of removing untrapped glucose during liposome preparation and by the type of ganglioside incorporated into the lipid bilayer.

Animals↗
PubMed1985

Influence of glycolipids on immune reactions of phospholipid antigens in liposomes.

Complement-dependent immune damage to liposomes mediated by a murine monoclonal antibody to the liposomal bilayer was completely inhibited by ceramide tetrasaccharide (globoside) at an 8% concentration in the liposomes. Lower concentrations of globoside, or higher concentrations of ceramide tri-, di-, or monohexoside, were not inhibitory. At a globoside concentration of 5.8%, inhibition of the monoclonal antibody activity was reduced and inhibition was related to antibody concentration; but at 2% globoside, suppression of antibody activity was not observed at all. Analysis of space-filling models revealed that at 8% globoside the distance between adjacent tetrasaccharides of globoside approached the dimensions of the antigen-binding end of a 7S immunoglobulin molecule. We therefore propose that globoside, and perhaps other glycolipids, can exert steric hindrance to the binding of extracellular proteins to nonglycolipid constituents of the lipid bilayer. We conclude that microheterogeneity among polar groups of glycolipids may be a novel mechanism for allowing selective access of proteins to phospholipids on the lipid bilayer.

Animals↗
PubMed1984

Transient autoantibodies with elevated complement levels in common viral diseases.

Autoantibodies including rheumatoid factor (RF), anti-DNA antibody (ADA), and anti-nuclear factor (ANF) in addition to cold agglutinin and heterophil antibody titers were tested for in a total of 219 patients with common viral diseases. The diseases included varicella, influenza, measles, mumps, herpes zoster, hand-foot-mouth syndrome, and exanthem subitum . A high incidence of RF (23%) was demonstrated in varicella patients, and ADA and ANF (16% and 12%, respectively) were most frequently detected in the influenza cases. Those autoantibodies were most frequently found in patients with influenza. Each serum complement component and total hemolytic complement (CH50) were also assayed. Elevated levels of the fourth (C4) and ninth (C9) components of complement, along with elevated CH50, were observed in most patients. Follow-up studies indicated that those autoantibodies as well as other antibodies disappeared 3 to 8 weeks after the onset of infection. The present study indicates that substantial but transient alterations in the immune system accompanied by autoimmune phenomena and elevated levels in the complement components can occur in viral infections.

Adolescent↗
PubMed1982

Species-specific glycoproteins of the human red cell membrane.

Specific antiserum of human red cells was prepared from rabbit anti-human red cell serum by absorption with red cells of horse, hog, dog and Japanese monkey. This antiserum proved specific for human red cells regardless of blood types ABO and MN as demonstrated by the hemagglutination test. Sialoglycoproteins were extracted with lithium diiodosalicylate and isolated through chromatographic procedures from human red cell membranes, and showed inhibitory activity for the specific antiserum as well as for anti-M and anti-N sera. The isolated glycoproteins corresponded to the sialoglycoproteins on the basis of SDS-PAG electrophoresis. The inhibitory activity of the sialoglycoproteins for the specific antiserum was lost after the substance was treated with sialidase for 24h. A moderate reduction of the inhibitory activity for anti-M and anti-N sera but not for the specific antiserum was seen after treatment for 1h. These results showed that the receptors for the species-specific antiserum were more resistant towards sialidase treatment.

ABO Blood-Group System↗