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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 811 records · Page 45Linked to original sources
PubMed1984

A grating laser microscope for measurements of blood flow velocity in microvessels.

A velocimeter for measurements of blood flow velocity in microvessels was constructed with a microscope, a grating, a photomultiplier and a wave-period measuring circuit. A differential detection system seemed to be useful when the probing area was extremely small. A pulsating flow velocity contour and the velocity reduction caused by an application of noradrenaline were on-line recorded in an arteriole of foot web of frogs.

Animals↗
PubMed1984

Significance of serum tumor markers in patients with carcinoma of the ovary.

A comparison of preoperative serum tumor markers (lactate dehydrogenase, lactate dehydrogenase isoenzymes, alpha-hydroxybutyrate dehydrogenase, alkaline phosphatase, aldolase, leucine aminopeptidase, cholinesterase, erythrocyte sedimentation reaction, carcinoembryonic antigen, alpha-fetoprotein, and beta 2-microglobulin) was made in 76 patients with ovarian or uterine cancer. Sixty-six patients with benign ovarian tumor served as control subjects. From analysis of each tumor marker the greatest positive results were obtained with the markers beta 2-microglobulin (57.1%), lactate dehydrogenase (53.1%), and hydroxybutyrate dehydrogenase (46.2%) for patients with carcinoma of the ovary. The use of these marker combinations in all ovarian cancer patients resulted in a marked increase of the positive rate from 57.1 to 85.2%. In stage I cases, the positive rate increased from 40.6 to 63.6%.

Adenocarcinoma↗
PubMed1984

Characterization of an established cell line from human immature teratoma of the ovary and effects of retinoic acid on cell proliferation.

A human immature teratoma cell line was established from tumor tissue of the ovary. The cell line, designated YK , synthesized and secreted alpha-fetoprotein, but there was a gradual decrease in the synthesis of this protein during serial passage. The doubling time at passage 43 was about 20.3 hr, and the plating efficiency was 30 to 40%. Tumorigenicity of the cell line in athymic nude mice was 100% even when 10(4) cells were inoculated s.c. When the cell line was cultivated for 5 days in the presence of 80 microM retinoic acid, proliferation was completely inhibited, while alpha-fetoprotein secretion into the medium was increased. Specific lactate dehydrogenase activity in the tumor grown in nude mice as well as in the cultured cells was 8 times higher than that in the original tumor. The activity of alpha-hydroxybutyrate dehydrogenase in the original tumor was similar to that in the tumor grown in nude mice, while the activity in the cultured cells was about 2.5 times higher than those in both original tumor and the tumor grown in nude mice. The original tumor had all five ordinary bands of lactate dehydrogenase isoenzymes. In contrast, both the cultured cells and the tumor grown in nude mice had a characteristic band which was considered to have similar electrophoretic mobility as testicular lactate dehydrogenase X isoenzyme in humans.

Animals↗
PubMed1984

Early cellular responses in the peritoneal cavity of mice to antitumor immunomodulators.

The early cellular responses to antitumor immunomodulators and conventional inducers, especially the polymorphonuclear leukocyte (PMN) responses, were examined in the peritoneal cavity of mice to investigate their effect on primary defense mechanisms. Immunomodulators were classified into 5 groups in terms of PMN response on the basis of its duration (declining or persistent) and extent (high or low induction): 1) TAK (beta-1,3-glucan)-type (high, persistent), 2) lentinan-type (high, declining), 3) yeast mannan-type (low, declining), 4) LPS (lipopolysaccharide)-type (low, persistent), 5) others (no effect). Since the general PMN response is of the declining type, the persistence of PMN with TAK- and LPS-type immunomodulators is a characteristic of the PMN-inducing activity. With respect to the extent, TAK- and lentinan-type immunomodulators induced larger numbers of PMN and macrophages than conventional inducers. These results suggest that some types of immunomodulators have effects on the early host-defense mechanism. From the viewpoint of the general self-defense mechanism we also compared these PMN responses with those to bacteria and to tumor inoculation, and the properties of substances inducing high PMN response, i.e., those with the quality of "foreignness," are discussed.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1984

Lymphoid cell subpopulations infiltrating into autologous rat tumors undergoing rejection.

Lymphoid cell subpopulations infiltrating into autografts of methylcholanthrene-induced sarcomas in rats immunized with autologous tumor cells were identified in terms of immunohistochemical and cytofluorographic techniques using various monoclonal antibodies raised against different classes of rat lymphohemopoietic cells. These antibodies included in this study directed to rat T-cell antigens corresponding to mouse Lyt-1 (RLyt-1) and Lyt-2,3 antigens (RLyt-2) and to W3/25 antigen expressed on a particular subset of rat T-cells with helper function, as well as to rat granulocyte-macrophage-specific antigen (RGM-1). Histological studies demonstrated that the autografts of highly antigenic tumors introduced to the primary hosts were completely rejected following massive immigration of lymphoid cells into the tumor sites, which was not observed in progressively growing, minimally antigenic tumors. These lymphoid cells found within regressing highly antigenic tumor autografts were identified mostly to be T-cells bearing RLyt-1 (approximately 70%), and more than two-thirds of these T-cells expressed RLyt-2 antigen. In contrast to T-cells, macrophages and B-cells, each of which could be recognized by the presence of either RGM-1 antigen or immunoglobulin on their cell surfaces, appeared to have a minimal role in the rejection of autochthonous tumors, as reflected by their less frequent appearance within the tumor tissues during the rejection process.

Animals↗
PubMed1983

Comparison of plasma oxytocin levels during spontaneous labor and labor induced by amniotomy, prostaglandin F2 alpha, and prostaglandin E2.

Plasma concentrations of oxytocin in nine spontaneous labors (group 1), nine amniotomy-induced labors (group 2), six prostaglandin F2 alpha-induced labors (group 3), and five prostaglandin E2-induced labors (group 4) were determined at the stages of 1 to 7 days preceding the onset of labor, onset of labor, and established labor, by means of unextracted radioimmunoassay. The levels of oxytocin in the stage preceding the onset of labor in group 1 were not significantly different from the levels of oxytocin in the corresponding stages in groups 2, 3, and 4. However, the levels of oxytocin in the stages of onset of labor and established labor in group 1 were significantly higher than those in the corresponding stages in groups 2, 3, and 4. These results suggest that oxytocin plays a leading role in the onset and progress of spontaneous labor, whereas something other than oxytocin might be involved in the labor induced by amniotomy alone or by prostaglandins.

Adult↗
PubMed1983

The source of oxygen in the reaction catalysed by collagen lysyl hydroxylase.

The synthetic peptides (Pro-Pro-Gly)5 and (Ile-Lys-Gly)5-Phe were hydroxylated with collagen prolyl hydroxylase and lysyl hydroxylase in an 18O2 atmosphere. The oxygen atoms in the hydroxy groups of hydroxyproline and hydroxylysine were 87% and 6.5% respectively derived from the atmospheric 18O2. The results are consistent with those reported previously for proline hydroxylation in vivo [Fujimoto & Tamiya (1962) Biochem. J. 84, 333-335; Prockop, Kaplan & Udenfriend (1962) Biochem. Biophys. Res. Commun. 9, 192-196; Fujimoto & Tamiya (1963) Biochem. Biophys. Res. Commun. 10, 498-501; Prockop, Kaplan & Udenfriend (1963) Arch. Biochem. Biophys. 101, 499-503] and in vitro [Cardinale, Rhoads & Udenfriend (1971) Biochem. Biophys. Res. Commun. 43, 537-543] and for lysine hydroxylation in vivo [Fujimoto & Tamiya (1963) Biochem. Biophys. Res. Commun. 10, 498-501]. In view of the similarities of these two oxygenase-type hydroxylation reactions the participation of intermediates is proposed, the oxygen atoms of which are exchangeable with those of water. The atmospheric oxygen atoms incorporated into the intermediate must be equilibrated with water oxygen atoms in the slower lysyl hydroxylase reaction.

Chemical Phenomena↗
PubMed1983

Ligation of endogenous tRNA 3' half molecules to their corresponding 5' halves via 2'-phosphomonoester,3',5'-phosphodiester bonds in extracts of Chlamydomonas.

tRNA preparations from Chlamydomonas and wheat germ contain small amounts of tRNA 5' halves and corresponding 3' halves. Incubation of cell-free extracts from the two sources with [gamma-P]ATP yielded 5'-P-labeled tRNA 3' halves which were joined to their corresponding 5' counterparts to form mature tRNA containing 2'-phosphomonoester,3', 5'-phosphodiester bonds. tRNA 3' halves labelled with T4 kinase were purified, sequenced and also joined to their 5' counterparts. It is proposed that these tRNA halves may be intermediates of the tRNA splicing process, and that the RNA kinase and ligase activities observed here are part of the tRNA splicing complex.

Journal Article↗