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T Takayasu

Publications and source records attributed to T Takayasu.

At least 73 records · Page 4Linked to original sources
PubMed1988

Human-type blood group activities on chimpanzee erythrocytes with special reference to M and N.

Human-type blood group activities on the red blood cells (RBCs) of three chimpanzees were individually examined with commercial mouse monoclonal antibodies (anti-A, -B, -H, -M, -N, -Lea, and -Leb) as well as lectins (UEA-I and VGA) and conventional polyclonal antisera for the systems ABO, MN, Lewis, Rh-Hr, P, Kell, Kidd, Duffy, and Lutheran. For further analysis of the MN antigens, treatment of the RBCs with sialidase, trypsin, and chymotrypsin were employed. The activities recognized among the three chimpanzees were A, H, M, N, Leb, c, S, k, and Jka. The RBCs of the three individuals possessed the A antigen which showed the same serologic activity as the human A1. Those chimpanzee RBCs showed higher H-activity than the human A1 RBCs. The Lewis b activity was revealed by the absorption-elution method. The RBCs of the three individuals showed a reactivity to the polyclonal anti-M reagents, which was affected by both the sialidase and trypsin treatment. The RBCs of two individuals were agglutinated with the monoclonal anti-N. The receptor was sensitive to sialidase and chymotrypsin. The RBCs of the three individuals, however, did not react with the monoclonal anti-M or with one of the polyclonal anti-N. These results indicate structural differences in the glycophorins and MN antigens between the human and chimpanzee.

ABO Blood-Group System↗
PubMed1988

Immunocytochemical study on the ultrastructural localization of human-type ABO (H)-blood group activities in a macaque (Macaca irus).

The immunocytochemical study on the ultrastructural localization of human-type ABO(H)-activities in a crab-eating macaque (Macaca irus) was carried out by using postembedding and immuno-gold staining method. The tissue specimens examined were the esophagus, stomach (St), small intestine (Si), large intestine, liver, kidney, and pancreas. The specimens from these organs and submandibular gland (Sg) of a human (O-group) were used as staining reaction controls. Primary and secondary antibodies were commercially obtained mouse monoclonal anti-A, -B, -H (IgM), and goat anti-mouse IgM labeled with colloidal gold particles (luminal diameter 20 nm), respectively. The results were as follows: (1) In macaque specimens, only A-activity could be observed as the location of gold particles on the peripheral rim of serous secretory granules (Sg) and of epithelial cells (esophagus), the mucous droplets in epithelial cells and brush border (St, Si), the intracellular secretory canaliculi [ISC (St)] and the zymogen granules and secretory ducts (pancreas). Gold particles could be also noted at the Golgi apparatus and nascent secretory granules. (2) By periodic acid-thiocarbohydrazide-osmium tetroxide (PA-TCH-OS) reaction, hexose-rich neutral mucopolysaccharides were noted on the peripheral rim of serous secretory granules (Sg), the mucous droplets (St, Si), the ISC (St), and the brush border (Si). Such a distributional pattern corresponded well with that of gold particles, indicating that the substances were responsible for ABO(H)-activities.

ABO Blood-Group System↗
PubMed1988

Protein kinase C activation aggravates hypoxic myocardial injury by stimulating Na+/H+ exchange.

The physiological and pathophysiological roles of protein kinase C activation were investigated in cultured mouse myocardial cells. First, effects of 12-O-tetra-decanoyl-phorbol-13-acetate (TPA), a potent activator of protein kinase C, on the intracellular pH (pHi) and cytosolic free Ca2+ level [( Ca2+]i) were studied, using 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) and quin-2, respectively. In the presence of the Ca ionophore A23187, TPA induced a rise in pHi by activating amiloride-sensitive Na+/H+ exchange and also produced a rise in [Ca2+]i above that seen with A23187 alone. These effects were totally inhibited by amiloride. Second, the effect of TPA on hypoxia-induced myocardial cell injury was evaluated. The addition of TPA to the culture medium enhanced creatine kinase release from hypoxic myocardial cells (95% N2 + 5% CO2). This effect was markedly suppressed by the addition of amiloride. These data suggests that protein kinase C activation aggravates hypoxic myocardial injury, presumably by inducing Ca2+ overload. This event is secondary to activation of Na+/Ca2+ exchange through accelerated influx of Na+ into the cells as a result of Na+/H+ exchange stimulation by protein kinase C.

Animals↗
PubMed1988

Ouabain inhibits intracellular pH recovery from acidosis in cultured mouse heart cells.

Myocardial ischaemia induces cytosolic acidification, which promotes cardiac damage, dysfunction or arrhythmia. In this study, we investigated the effect of ouabain on the intracellular pH (pHi) in cultured mouse ventricular cells, using 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). The average resting pHi in myocytes was 7.19. After myocytes were acid-loaded with NH4Cl, the pHi recovered from acidosis to the resting level within a few minutes via amiloride-sensitive Na+/H+ exchange. Ouabain inhibited this pHi recovery dose-dependently with half-maximal inhibition at 3 X 10(-5) M, but did not suppress the ionophore monensin-induced pHi elevation. The inhibition of the pHi recovery from acidosis by ouabain is possibly caused by an inhibition of amiloride-sensitive Na+/H+ exchange, which is secondary to a suppression of Na+ efflux through (Na+, K+) pump. Above results demonstrate the possibility that digitalis promotes intracellular acidosis or inhibits the pHi recovery from acidosis in ischaemic myocardium.

Acidosis↗
PubMed1988

Differences in regulatory mechanisms of atrial and ventricular muscle contraction in bovine heart.

The purpose of this study was to characterize the regulatory mechanisms of atrial muscle contraction. Natural actomyosin (NAM) and tropomyosin-troponin (TM-TN) complex were prepared from atrial and ventricular muscle of the same bovine heart. The results were as follows: (1) Atrial NAM was more sensitive to Ca2+ than was ventricular NAM: the pCa required for 50% ATPase activation was 5.96 +/- 0.10 vs. 5.63 +/- 0.07, (mean +/- SE; n = 6; p less than 0.01); (2) reconstitution of desensitized actomyosin of rabbit skeletal muscle plus atrial or ventricular TM-TN complex produced higher Ca2+ sensitivity in atrial muscle than in ventricular muscle: the pCa required for 50% ATPase activation was 6.48 +/- 0.10 vs. 6.23 +/- 0.15 (n = 3; p less than 0.05); (3) the amount of inorganic phosphate covalently bound to atrial NAM was equivalent to that bound to ventricular NAM; (4) SDS-polyacrylamide gel electrophoresis of the two NAMs revealed several protein bands of different mobility from 16,000 to 30,000 daltons; and (5) the superprecipitation response of atrial NAM was characterized by a stepwise change in turbidity after the addition of MgATP, in contrast to the biphasic pattern of ventricular NAM. These data suggest that the free Ca ion concentration required for atrial muscle contraction is lower than that required for ventricular muscle contraction and that the difference is attributable to differences in atrial and ventricular regulatory proteins.

Actomyosin↗
PubMed1985

Further comparative studies on chemical properties of carcinoembryonic antigen in tumor tissues and closely related antigens in adult feces and meconium.

The chemical structure of carcinoembryonic antigen (CEA) and two closely related antigens, normal fecal antigen-2 (NFA-2) in normal adult feces and nonspecific cross-reacting antigen-2 (NCA-2) in the meconium, were further analyzed comparatively. The NH2-terminal amino acid sequence of NCA-2 was newly determined to position 18 and found to be identical to that so far determined for CEA- and NFA-2. After proteolytic digestion with chymotrypsin or protease V8, the digests of these antigens showed two groups of fragments upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One consisted of the sharply banded fragments which were identical in all antigens and stained only with Coomassie brilliant blue (CBB) (five bands in the range 2500-10,000 daltons for chymotrypsin and 11 bands in the range 8000-35,000 daltons for protease V8, respectively), and the other consisted of the dispersed fragments which had variable mol. wts in the range 10,000-100,000 and were stainable with both CBB and periodic acid-Schiff reagent. Elution profiles of CEA, NFA-2, and NCA-2 from lectin columns, especially from concanavalin A-Sepharose columns, suggested some differences in oligosaccharide chains between them. These results indicate that the fundamental chemical structure of these antigens seems to be very similar to one another and is divided into two parts; an homologous portion(s) which is common to all three antigens and contains no sialylated sugar components, and a heterogeneous portion(s) which is variable among these antigens and contains sialylated sugar components.

Adult↗
PubMed1983

Structure and location of asparagine-linked oligosaccharides in the Fc region of A human immunoglobulin D.

Seven kinds of asparagine-linked oligosaccharides were bound to the Fc region of a human immunoglobulin D(NIG-65). The oligosaccharides quantitatively released from four species of glycopeptides by digestion with almond glycopeptidase, were separated by Bio-Gel p-4 column chromatography and were purified further by thin-layer chromatography. The sugars were identified with GC-MS following the permethylation of respective oligosaccharide. To Asn-68 (NIG-65 Fc numbering (1)), two kinds of high-mannose-type oligosaccharides were bonded. To Asn-159, a kind of hybride-type and two kinds of bisected complex-type oligosaccharides were attached. From Asn-210, four kinds of bisected complex-type oligosaccharides were isolated.

Animals↗
PubMed1983

Comparative studies on the structure of the light chains of human immunoglobulins. IV. Assignment of a subsubgroup.

Amino acid sequence analysis was done on a human lambda Bence Jones protein NIG-64 with the major objective of determining the sequence of the variable region. Nineteen tryptic peptides covering 216 residues were isolated from the completely reduced and aminoethylated protein, and 17 of these were completely sequenced. These comprised the entire variable region and 11 from the constant region. For the remaining peptides covering the rest of the constant region, only partial sequences or the amino acid compositions were determined. All the tryptic peptides could be arranged in order on the basis of the above results and homology with other human lambda light chains of the same isotype. The sequence of the variable region of the protein is highly homologous with that of protein New of subgroup V lambda I as compared with other proteins of the same subgroup, suggesting that subgroup V lambda I may be further divided into subsubgroups, namely subsubgroups V lambda I-1 and V lambda I-2.

Amino Acid Sequence↗
PubMed1982

Immunological characterization and structural studies of normal fecal antigen-1 related to carcinoembryonic antigen.

Normal fecal antigen-1 (NFA-1), which is a carcinoembryonic antigen (CEA)-related glycoprotein with a mol. wt of 20,000-30,000, was purified from normal adult feces by immuno-adsorption, gel filtration and ion exchange chromatography. Highly purified NFA-1 was partially cross-reactive with CEA but antigenically unrelated to nonspecific cross-reacting antigen (NCA) which was also cross-reactive with CEA. NFA-1 also had a unique determinant not present in CEA or other related antigens including NCA. In a solid-phase RIA system, the reactivity of NFA-1 with a specific anti-CEA antiserum was much stronger than that of NCA. Although digestion with Pronase E did not affect the antigenicity of NFA-1, reduction and alkylation destroyed its antigenic reactivity. The total amount of carbohydrate in NFA-1 was 13.3%, compared to 52.4% in CEA and 21.6% in NCA. The amino acid composition of NFA-1 was similar to that of CEA. The sequence of the first 10 NH2-terminal amino acids in NFA-1 was Ala-Glu-Pro-Pro-Lys-Pro-Phe-Ile-(Thr)-Ser. This was totally different from that of the first NH2-terminal amino acids of CEA isolated from tumor tissue.

Amino Acid Sequence↗